amdgcn: Convert get_num_groups to clc

Signed-off-by: Jan Vesely <jan.vesely@rutgers.edu>
Reviewed-By: Aaron Watry <awatry@gmail.com>
llvm-svn: 346081
GitOrigin-RevId: 0e95b6a5793fb9f2f9ad775d78e40f0cace5ebf3
13 files changed