[AMDGPU] gfx11 vinterp instructions MC support

A new instruction encoding. Some of these instructions were previously VOP3
encoded.

Contributors:
Carl Ritson <carl.ritson@amd.com>

Patch 11/N for upstreaming of AMDGPU gfx11 architecture.

Depends on D125824

Reviewed By: critson

Differential Revision: https://reviews.llvm.org/D125989