add DISCO_L496AG + STModCellular BG96 support

[soleilplanet]

Summary of changes

[X] I confirm this contribution is my own and I agree to license it with Apache 2.0.

[X] I confirm the moderators may change the PR before merging it in.

For new board enablements only:

[X] I confirm the board is Mbed Enabled and passes the Mbed Enabled test set.

[X] I confirm the contribution has been tested properly and the tests results for TESTS are attached.

[X] I confirm mbed-os.lib and mbed-cloud-client.lib hashes or the content in folders mbed-os and mbed-cloud-client were not modified in order to pass the tests.

• Maintainers of this repository update the Mbed OS and Client hashes.
• Please report any issues through issues in relevant repositories.

Add support for DISCO_L496AG + STModCellular BG96.
Integration tests all passed, Pelion E2E tests all passed except for update test due to python package issue. Update campaign succeeded with manual 'mbed dm' commands.
disco_l496ag_external_kvstore_pelion_e2e_test.log
disco_l496ag_external_kvstore_integration_test.log

[iot-pdmc]

Thanks for your changes.
@ARMmbed/pdmc-integrators please review.

[teetak01]

@soleilplanet does this not depend on ARMmbed/mbed-os#12411 ?

[soleilplanet]

@teetak01 yes, this depends on ARMmbed/mbed-os#12411, just forgot to put this information. Sorry about that.
I managed to get my python environment fixed, but the update test failed because it couldn't complete the the campaign within the specified timeout. (the default timeout is too short for NB-IoT network; my best record is 8 minutes, but it could take 30 minutes or longer, which depends on signal quality )
l496ag_stmodcellular_bg96_pelion_e2e_test.log

[teetak01]

Thanks for clarifying. I have already mentioned earlier for the testing team about this issue with the test-timeout.

[soleilplanet]

@teetak01 I've added an additional line and it is now not dependent on the Mbed-OS PR.

[teetak01]

Please rerun the the tests which the config change to see that the override works as expected.

[soleilplanet]

@teetak01 here are the logs with the new commit.
pelion_e2e_test_updated.log
l496ag_stmodcellular_bg96_mbed_os_integration_test.log

[teetak01]

Can you fix the configuration? I am not sure that will even compile? Having two identical entries in .json should not even pass Mbed CLI verification, or if it does, one of those parameters would get silently ignored.

[soleilplanet]

@teetak01 it would compile and here's the log with a dump of the mbed_app.json:
show_config_and_compile.log
I'm basically running a script to call:
cat mbed_app.json | grep -A40 'DISCO_L496AG'
mbed compile

Combining those two lines in one will not be able to build; you will see 'unresolved symbol to pal_plat_XXXXX()' in pal_plat_internalFlash.cpp during compilation and it will just fail. That's why I filed the PR in Mbed-OS at the first place.
(and I guess I would need to file an issue to the tools team)

by the way, I'm using all latest tools as I created a new VM for this test.

[soleilplanet]

@teetak01 I found that the build error I mentioned above is not observed after I upgraded python to 2.7.17 (was 2.7.12) with single line of 'components_add'
So I'm going to merge those two lines and test again.

[teetak01]

Yeah good. I was not able to reproduce the issue either.

[teetak01]

You could also rebase the PR.

[soleilplanet]

test logs with combined components_add:
integration_test_log_2.log
pelion_e2e_test_2.log

[teetak01]

build-only

[soleilplanet]

updated test log with new commit:
pelion_e2e_test_3.log
integration_test_log_3.log

[teetak01]

build-only

[teetak01]

@soleilplanet this would still require:

1. Add README entry for this board.
2. Squash the commits together
3. Rebase locally with master.

[soleilplanet]

@teetak01 I just squashed and rebased from master, but I'm not sure if that's the result you'd like to see. Would you please check?
Thanks!

[teetak01]

build-only

[iot-pdmc]

Test run: SUCCESS

---

Build artifacts

posted-by-tag: https://jenkins-client.isgtesting.com/job/mbed-os-example-pelion/

[teetak01]

Looks good, thanks @soleilplanet