docs: clarify MPU region parameter macros

[Old-Ding]

Summary

• Clarify that MemoryRegion_t.ulParameters uses port-specific MPU region parameter macros.
• Keep the existing portMPU_REGION_* examples for Cortex-M3/4 MPU ports.
• Document that ARMv8-M MPU ports such as CM23, CM33, CM52, CM55, CM85, and STAR_MC3 use the tskMPU_REGION_* values from task.h, which the port translates into MPU register settings.

Fixes #1384

Impact

This is a documentation-only change. It does not change any API, ABI, macro value, structure layout, configuration option, or port behavior.

Validation

• git diff --check -- include/task.h
• git diff --stat and git diff --word-diff -- include/task.h
• rg -n "Some ports, including the Cortex-M3/4 MPU ports|ARMv8-M MPU ports|MemoryRegion_t\.ulParameters|tskMPU_REGION|portMPU_REGION|xTaskCreateRestrictedStatic|vTaskAllocateMPURegions" include/task.h
• Static source check: ARMv8-M ports consume tskMPU_REGION_* from MemoryRegion_t.ulParameters.
• Static source check: Cortex-M3/4 MPU ports still consume portMPU_REGION_* from MemoryRegion_t.ulParameters.

Doxygen output was not generated locally because doxygen is not installed in this environment.

[sonarqubecloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube Cloud

[rawalexe]

Good clarification for a common source of confusion between portMPU_REGION_* and tskMPU_REGION_* macros across MPU port variants. No logic changes, comment-only. LGTM.