[Clang][AArch64] Add missing SME macros (#80293)

__ARM_STATE_ZA and __ARM_STATE_ZT0 are set when the compiler can parse 
the "za" and "zt0" strings in the SME attributes.

__ARM_FEATURE_SME and __ARM_FEATURE_SME2 are set when the compiler can 
generate code for attributes with "za" and "zt0" state, respectively.

__ARM_FEATURE_LOCALLY_STREAMING is set when the compiler supports the
__arm_locally_streaming attribute.