Added thumb mode support for threadX GNU ports on armv7a platforms.

[yajunxiaMS]

https://msazure.visualstudio.com/One/_workitems/edit/26105175/

PR checklist

• Updated function header with a short description and version number
• Added test case for bug fix or new feature
• Validated on real hardware

[github-actions]

Test Results ThreadX

475 tests  ±0   475 ✔️ ±0   2m 22s ⏱️ -1s
    5 suites ±0       0 💤 ±0 
    5 files   ±0       0 ❌ ±0 

Results for commit 6894f08. ± Comparison against base commit 776ea21.

♻️ This comment has been updated with latest results.

[github-actions]

Package	Line Rate	Branch Rate	Health
.home.runner.work.threadx.threadx.common.src	100%	100%	✔
Summary	100% (3827 / 3827)	100% (1993 / 1994)	✔

[github-actions]

Test Results SMP

540 tests  ±0   540 ✔️ ±0   4m 40s ⏱️ -2s
    5 suites ±0       0 💤 ±0 
    5 files   ±0       0 ❌ ±0 

Results for commit 6894f08. ± Comparison against base commit 776ea21.

♻️ This comment has been updated with latest results.

[github-actions]

Package	Line Rate	Branch Rate	Health
.home.runner.work.threadx.threadx.common_smp.src	100%	100%	✔
Summary	100% (4776 / 4791)	100% (2423 / 2430)	✔