[llvm] [AMDGPU][MC] Add dpp for V_PK_FMAC_F16 for GFX10 (PR #79598)

[Matt Arsenault via llvm-commits]

https://github.com/arsenm commented:

Do we need new codegen tests for making sure we use it for gfx10 and not for 11?

https://github.com/llvm/llvm-project/pull/79598