drm/amdgpu/gmc9: remove mmhub client duplicated case

Copy paste typo.
Reported-by: kernel test robot <lkp@intel.com>
Reviewed-by: Felix Kuehling <Felix.Kuehling@amd.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/amd/amdgpu/gmc_v9_0.c

@@ -269,7 +269,6 @@ static const char *mmhub_client_ids_arcturus[][2] = {
 	[14][1] = "HDP",
 	[15][1] = "SDMA0",
 	[32+15][1] = "SDMA1",
-	[32+15][1] = "SDMA1",
 	[64+15][1] = "SDMA2",
 	[96+15][1] = "SDMA3",
 	[128+15][1] = "SDMA4",