CMSIS-RTX

      - Enhance conditions to support Cortex-M52
      - Remove dependency on Device:Startup component

      First release of separate pack shipping RTX5 RTOS implementation for CMSIS-RTOS2 API.
      Changes since RTX 5.5.4:
      - Based on CMSIS-RTOS API V2.3.0 (processor affinity not supported).
      - Added support for Process Isolation: MPU Protected Zones, Safety Classes, Thread Watchdogs.
      - Requires CMSIS:OS Tick:SysTick component.
      - Reduced component variants: Library (Library_NS replacement), Source (Source_NS replacement).
      - Libraries for Arm Compiler 6 built with default wchar and enums size.
      - Added pre-built libraries for GCC, CLANG and IAR.
      - Removed support for legacy Arm Compiler 5.
      - Fixed osMessageQueueGetSpace when called from ISR after osMessageQueuePut and before returning from ISR.
      - Added de-allocation of Arm C library thread data (libspace) when thread is terminated.
      - Added Thread Entry wrapper (compatible with GDB stack unwind).
      - Updated SysTick implementation for OS Tick (initial count value).