[AArch64] Add support for Cortex-A520, Cortex-A720 and Cortex-X4 CPUs (#72395)

Cortex-A520, Cortex-A720 and Cortex-X4 are Armv9.2 AArch64 CPUs.

Technical Reference Manual for Cortex-A520:
   https://developer.arm.com/documentation/102517/latest/

Technical Reference Manual for Cortex-A720:
   https://developer.arm.com/documentation/102530/latest/

Technical Reference Manual for Cortex-X4:
   https://developer.arm.com/documentation/102484/latest/

Patch co-authored by: Sivan Shani <sivan.shani@arm.com>