[llvm] [AMDGPU][MC] Restrict op_sel in VOP3P dot instructions (PR #100485)

[Jun Wang via llvm-commits]

jwanggit86 wrote:

In the existing code, for all dot instructions for GFX940, op_sel must be 0, and op_sel_hi cannot be included. This latest commits apply the same restrictions to VOP3P dot instructions (v_dot4_*, v_dot8_*, and some v_dot2_*).

https://github.com/llvm/llvm-project/pull/100485