Mbed 5.10! Don't use deprecated functions.

[bmcdonnell-ionx]

Description

Stop using the newly-deprecated functions from rtos/Thread.h.

NB: suggest merging before 5.10 release (currently RC2)! But I leave it to you to do any additional needed testing/checks, since I only did a test build for one target (LPC4088).

For reference, here's the script I threw together to do most of the work: fixdep.zip. I ran that, then did a build, and fixed up the #includes.

Aside: this is further motivation for #7886.

Pull request type

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

[cmonr]

@bmcdonnell-ionx Thanks for the changes and the PR, but as of right now, we're being incredibly picky about PRs coming in for RC3. At this point, PRs that come in will be for broken functionality that was tested and validated in RC1 and RC2.

[kjbracey]

I have a PR on this already pending: #7980

[bmcdonnell-ionx]

@kjbracey-arm, I defer to your PR, and offered my additional content there.

@cmonr / @0xc0170, I suspect you'll want to remove the remaining label on this PR.