drm/radeon: Clean up errors in kv_smc.c

Fix the following errors reported by checkpatch:

ERROR: spaces required around that '=' (ctx:VxW)
Signed-off-by: GuoHua Chen <chenguohua_716@163.com>
Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/kv_smc.c

@@ -189,7 +189,7 @@ int kv_copy_bytes_to_smc(struct radeon_device *rdev,
 		if (ret)
 			return ret;
 
-		original_data= RREG32(SMC_IND_DATA_0);
+		original_data = RREG32(SMC_IND_DATA_0);
 
 		extra_shift = 8 * (4 - byte_count);