arm: Add support for Cortex-X1C CPU.

arm: Add support for Cortex-X1C CPU.

This patch adds the -mcpu support for the Arm Cortex-X1C CPU.

gcc/ChangeLog:

2022-11-09  Srinath Parvathaneni  <srinath.parvathaneni@arm.com>

	* config/arm/arm-cpus.in (cortex-x1c): Define new CPU.
	* config/arm/arm-tables.opt: Regenerate.
	* config/arm/arm-tune.md: Likewise.
	* doc/invoke.texi: Document Cortex-X1C CPU.

gcc/testsuite/ChangeLog:

2022-11-09  Srinath Parvathaneni  <srinath.parvathaneni@arm.com>

	* gcc.target/arm/multilib.exp: Add tests for Cortex-X1C.