iar export: fix invalid optmization flag - remove from misc

[0xc0170]

Description

The exported project uses project file to set optimization, we can provide this
via misc options. It was recently changed to Ol and this was not handled in our
scripts.

Fixes #11496

Pull request type

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

Reviewers

Release Notes

[0xc0170]

I was able to reproduce the failure. And test this fix, all working with it.

[0xc0170]

cc @OPpuolitaival - this should fix nightly failures for iar export.

[mark-edgeworth]

Can someone please check that this now works as expected with the IAR tools? Apparently the check would normally only be done on a nightly run (see https://jira.arm.com/browse/MBEDOSTEST-757 comment)

[0xc0170]

I manually tested, but one more test would be good 👍 Use blinky and export and compare to master

[0xc0170]

Can someone please check that this now works as expected with the IAR tools? Apparently the check would normally only be done on a nightly run (see https://jira.arm.com/browse/MBEDOSTEST-757 comment)

@OPpuolitaival In cases like this, if an exporter code changes, this PR could run at least few exporters for IAR (improvement for smart tester)

[0xc0170]

I vote for getting this in today, and check nightly in the morning.

[0xc0170]

CI started

[mbed-ci]

Test run: SUCCESS

Summary: 11 of 11 test jobs passed
Build number : 1
Build artifacts