[AArch64] Add missing HasNEON predicate in scalar FABD patterns
I was trying to compile with -march=+nosimd and hit the following assertion:
`Attempting to emit FABD64 instruction but the Feature_HasNEON predicate(s) are not met`.
This adds a HasNEON predicate to the patterns which was omitted in commit
21d9b33d62772c58267cc0aa725e35ac9a4661db for some reason.
The new code generation matches GCC with -mcpu=<cpu>+nosimd:
https://godbolt.org/z/n1Y7xh5jo
Differential Revision: https://reviews.llvm.org/D123491