binfmt_elf: Wire up AT_HWCAP3 at AT_HWCAP4

AT_HWCAP3 and AT_HWCAP4 were recently defined for use on PowerPC in commit
3281366a ("uapi/auxvec: Define AT_HWCAP3 and AT_HWCAP4 aux vector,
entries"). Since we want to start using AT_HWCAP3 on arm64 add support for
exposing both these new hwcaps via binfmt_elf.

Signed-off-by: Mark Brown <broonie@kernel.org>
Acked-by: Kees Cook <kees@kernel.org>
Reviewed-by: Anshuman Khandual <anshuman.khandual@arm.com>
Link: https://lore.kernel.org/r/20241004-arm64-elf-hwcap3-v2-1-799d1daad8b0@kernel.org


Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>