[llvm] [AMDGPU][MC]FMA-mix instructions should not be supported in GFX908 etc. (PR #109873)

[Matt Arsenault via llvm-commits]

================
@@ -1426,7 +1425,6 @@ def FeatureISAVersion9_4_Common : FeatureSet<
   [FeatureGFX9,
    FeatureGFX90AInsts,
    FeatureGFX940Insts,
-   FeatureFmaMixInsts,
----------------
arsenm wrote:

But the rename happened in 908, and then the rename got lost after that? I'm confused 

https://github.com/llvm/llvm-project/pull/109873