add platform MOTE_L152RC

[dudmuck]

This is platform https://developer.mbed.org/platforms/namote-72/
It is nearly identical to NUCLEO_L152RE.
Files in targets/hal/TARGET_STM/TARGET_STM32L1/ moved to subdirectory where the file needed to be modified for the platform.

[0xc0170]

Hello, can you sign cla please: http://developer.mbed.org/contributor_agreement/

Another thing, the half of commits here are synch with upstream, you either squash these or I'll run manually merge squash.

[ohagendorf]

This target development started before the reorganization of mbed\targets\hal\TARGET_STM folders. Perhaps it would be a good idea to adapt it to the current structure.

[dudmuck]

The hal reorg for this platform is mbed/targets/hal/TARGET_STM/TARGET_STM32L1.
The following files were moved from TARGET_STM32L1 to TARGET_NUCLEO_L152RE:
gpio_object.h
rtc_api.c
serial_api.c
sleep.c
This is to accommodate changes needed specific to L152RC device, so these for files are in the target subdirectory under TARGET_STM32L1. All files in TARGET_STM32L1 are those which work for all STM32L1 targets.

[ohagendorf]

It is not necessary to double files with minor differences, e.g. the serial_api.c. Please have a look into another hal folder, e.g. for the STM32F4. You can use defines to handle different number of uarts etc.

[dudmuck]

ok, duplicate files eliminated and replaced with #if defined()

[ohagendorf]

Yes, that is what I meant.

[0xc0170]

I'll merge this manually, will squash those commits and let you know once done (will close this).

[0xc0170]

Squashed Merged manually, via 809d8aa

Please retest, there was one merge conflict I had to resolve.