[QSPI] Add support for several STM disco boards

[adustm]

Description

This pull request enables QSPI feature for several STM platforms
DISCO_L476VG
DISCO_F746NG
DISCO_F413ZH
DISCO_F469NI (some modifications versus current implementation)

(DISCO_L475VG_IOT01A is already supported in the feature-qspi branch)
(DISCO_F769NI and DISCO_L496AG are on going work, and will be pushed later in another PR)

Pull request type

[ ] Fix
[ ] Refactor
[ ] New target
[X] Feature
[ ] Breaking change

[0xc0170]

Changes look good to me. I am not sure about first 2 commits (they are already on the branch aren't they) ? (Github does not even show them in the full diff here)
In case yes, can you please rebase, I'll trigger CI right away then

[adustm]

Hello @0xc0170
Could you detail, please ?

continuous-integration/jenkins/pr-head — This commit cannot be built

[0xc0170]

Error: mbed_retarget.cpp@218,0: #289: no instance of constructor “mbed::UARTSerial::UARTSerial” matches the argument list for NRF52840_DK , might be the recent rebase, investigating now

Not related to this PR

[0xc0170]

Can you please rebase? I pushed an update to resolve the bad rebase (the failing build builds locally).

[adustm]

@0xc0170

Can you please rebase? I pushed an update to resolve the bad rebase (the failing build builds locally).

Done.

I am not sure about first 2 commits (they are already on the branch aren't they) ?

You're right. I've removed them

[0xc0170]

/morph build

[mbed-ci]

Build : SUCCESS

Build number : 1760
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/6638/

Triggering tests

/morph test
/morph uvisor-test
/morph export-build
/morph mbed2-build

[mbed-ci]

Exporter Build : FAILURE

Build number : 1397
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/6638/

[mbed-ci]

Test : SUCCESS

Build number : 1567
Test logs :http://mbed-os-logs.s3-website-us-west-1.amazonaws.com/?prefix=logs/6638/1567

[0xc0170]

/morph export-build

[mbed-ci]

Exporter Build : SUCCESS

Build number : 1407
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/6638/