[llvm] [AMDGPU] Don't DEALLOC_VGPRS from callable functions (PR #72245)

[Jannik Silvanus via llvm-commits]

https://github.com/jasilvanus commented:

All my comments have been addressed, looks reasonable to me.

Leaving approval to others who know this code better.

https://github.com/llvm/llvm-project/pull/72245