PSOC6: Fixes for serial hal driver, asynchronous mode.

[lrusinowicz]

Description

This commit fixes a number of more and less subtle bugs in a serial hal driver for PSoC6. Mostly TX/RX typos and incorrect events processing.

mbed tests log:
tests_sequana_gcc_20190114.log

Pull request type

[x] Fix
[ ] Refactor
[ ] Target update
[ ] Functionality change
[ ] Docs update
[ ] Test update
[ ] Breaking change

Reviewers

[ciarmcom]

@lrusinowicz, thank you for your changes.
@ARMmbed/mbed-os-maintainers please review.

[cmonr]

CI started

[0xc0170]

One breakage on master needs to be addressed asap, the current build was aborted and will be restarted within today.

[mbed-ci]

Test run: FAILED

Summary: 1 of 7 test jobs failed
Build number : 1
Build artifacts

Failed test jobs:

• jenkins-ci/mbed-os-ci_build-IAR

[0xc0170]

Failures are not related (only errors I spot are from not supported tests, no real errors). I'll check once again and restart CI if that is true

[0xc0170]

CI restarted

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 2
Build artifacts

[lrusinowicz]

@0xc0170
Hi Martin,
Unfortunately, I have found one another fix required for asynchronous API in this file. Would it be OK for me to amend this PR at this stage, or should I prepare another one?

[0xc0170]

Lets amend it here, I set it as needs work

[0xc0170]

All fixed now?

[lrusinowicz]

@0xc0170
Yes, now it's complete.

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 12 of 12 test jobs passed
Build number : 3
Build artifacts