build_api script : separate PeripheralPins.o

[jeromecoutant]

Description

This is done with @0xc0170 advice...
#7193 (comment)

Goal is to compile peripheral pins as separate object files in OS2

Pull request type

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

[cmonr]

👍

[cmonr]

/morph build

[mbed-ci]

Build : SUCCESS

Build number : 2463
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/7353/

Triggering tests

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

[mbed-ci]

Exporter Build : SUCCESS

Build number : 2092
Build artifacts/logs : http://mbed-os.s3-website-eu-west-1.amazonaws.com/?prefix=builds/exporter/7353/

[mbed-ci]

Test : SUCCESS

Build number : 2239
Test logs :http://mbed-os-logs.s3-website-us-west-1.amazonaws.com/?prefix=logs/7353/2239

[cmonr]

@jeromecoutant Doing a review of another PR, it dawned on me that this PR addition didn't update the comment block above. Would you mind submitting another PR with a comment addressing what PeripheralPins.o is?

(I know what and why, but it's more about keeping in line with the existing documentation.)