arm64: handle PKEY/POE faults

arm64: handle PKEY/POE faults

If a memory fault occurs that is due to an overlay/pkey fault, report that to
userspace with a SEGV_PKUERR.

Signed-off-by: Joey Gouly <joey.gouly@arm.com>
Cc: Catalin Marinas <catalin.marinas@arm.com>
Cc: Will Deacon <will@kernel.org>
Reviewed-by: Catalin Marinas <catalin.marinas@arm.com>
Link: https://lore.kernel.org/r/20240822151113.1479789-17-joey.gouly@arm.com
[will: Add ESR.FSC check to data abort handler]
Signed-off-by: Will Deacon <will@kernel.org>