Add memory protection support to RISC-V port

[vishwamartur]

Related to #908

Add memory protection support to the RISC-V port.

• Memory Protection Configurations and Settings

  • Add memory protection-related configurations and settings in portable/GCC/RISC-V/portmacro.h and portable/IAR/RISC-V/portmacro.h.
  • Define macros for enabling and disabling memory protection in both files.

• Critical Section Handling

  • Update the portENTER_CRITICAL and portEXIT_CRITICAL macros in portable/GCC/RISC-V/portmacro.h and portable/IAR/RISC-V/portmacro.h to handle memory protection.

• Chip-Specific Extensions

  • Add memory protection-related definitions and macros in portable/GCC/RISC-V/chip_specific_extensions/RISCV_MTIME_CLINT_no_extensions/freertos_risc_v_chip_specific_extensions.h and portable/IAR/RISC-V/chip_specific_extensions/RV32I_CLINT_no_extensions/freertos_risc_v_chip_specific_extensions.h.
  • Define macros for saving and restoring memory protection context in both files.

• Port Functions

  • Add functions for enabling and disabling memory protection in portable/GCC/RISC-V/port.c and portable/IAR/RISC-V/port.c.

Working on still: portASM.s planning to implement ASAP