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

[Matt Arsenault via llvm-commits]

arsenm wrote:

> Why is this not supported on gfx11? "Table 30. Which instructions support DPP" in the RDNA3 ISA doc lists no exception for v_pk_fmac_f16.


It's there, but not spelled out (it says "V_PK_*")

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