[AArch64][SVE2] Add the SVE2.1 fclamp instructions

This patch adds the assembly/disassembly for the following instructions:

FCLAMP : Floating-point clamp to minimum/maximum number

The reference can be found here:
https://developer.arm.com/documentation/ddi0602/2022-09

Differential Revision: https://reviews.llvm.org/D136358