arm: add support for Cortex-A78 and Cortex-A78AE

arm: add support for Cortex-A78 and Cortex-A78AE

This patch introduces support for Cortex-A78 [0] and Cortex-A78AE [1]
cpus.

	[0]: https://www.arm.com/products/silicon-ip-cpu/cortex-a/cortex-a78
	[1]: https://www.arm.com/products/silicon-ip-cpu/cortex-a/cortex-a78ae

OK for master branch ?

kind regards
Przemyslaw Wirkus

gcc/ChangeLog:

	* config/arm/arm-cpus.in: Add Cortex-A78 and Cortex-A78AE cores.
	* config/arm/arm-tables.opt: Regenerate.
	* config/arm/arm-tune.md: Regenerate.
	* doc/invoke.texi: Update docs.