To enable AARCH64 native instruction support for Openssl,
some interfaces must be implemented. OPENSSL_cpuid_setup()
allows to probe the supported features of the platform.
Add ArmReadIdAA64Isar0Reg() to read the AA64Isar0, containing
Arm64 instruction capabilities.
A similar ArmReadIdAA64Isar0() function is available in the ArmPkg,
but the CryptoPkg where OPENSSL_cpuid_setup will reside cannot rely
on the ArmPkg.
Signed-off-by: Pierre Gondois <pierre.gondois@arm.com>