arm64/cpufeature: Add remaining feature bits in ID_AA64MMFR0 register

arm64/cpufeature: Add remaining feature bits in ID_AA64MMFR0 register

Enable EVC, FGT, EXS features bits in ID_AA64MMFR0 register as per ARM DDI
0487F.a specification.

Suggested-by: Will Deacon <will@kernel.org>
Signed-off-by: Anshuman Khandual <anshuman.khandual@arm.com>
Reviewed-by: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: Will Deacon <will@kernel.org>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Suzuki K Poulose <suzuki.poulose@arm.com>
Cc: linux-arm-kernel@lists.infradead.org
Cc: linux-kernel@vger.kernel.org
Link: https://lore.kernel.org/r/1593748297-1965-2-git-send-email-anshuman.khandual@arm.com
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>