[AMDGPU][MC] Corrected parsing of registers

See bug 41280: https://bugs.llvm.org/show_bug.cgi?id=41280

Reviewers: artem.tamazov, arsenm

Differential Revision: https://reviews.llvm.org/D60621

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@358581 91177308-0d34-0410-b5e6-96231b3b80d8
3 files changed