arm64: errata: Calling enable functions for CPU errata too

Currently we call the (optional) enable function for CPU _features_
only. As CPU _errata_ descriptions share the same data structure and
having an enable function is useful for errata as well (for instance
to set bits in SCTLR), lets call it when enumerating erratas too.

Change-Id: If9eff7dd87d7ebcf8ee44ae0cc326f91e2c16af8
Signed-off-by: Andre Przywara <andre.przywara@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>
Git-commit: 8e2318521bf5837dae093413f81292b59d49d030
Git-repo: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux


[neeraju@codeaurora.org: resolve trivial merge conflicts]
Signed-off-by: Neeraj Upadhyay <neeraju@codeaurora.org>