Revert "Revert "[AMDGPU] const-fold imm operands of (#71669)

amdgcn_update_dpp intrinsic (#71139)""

This reverts commit d1fb9307 and fixes
the lit test clang/test/CodeGenHIP/dpp-const-fold.hip

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Authored-by: Pravin Jagtap <Pravin.Jagtap@amd.com>