drm/radeon: fix typo in cik_select_se_sh()

Signed-off-by: Alex Deucher <alexander.deucher@amd.com>

drivers/gpu/drm/radeon/cik.c

@@ -1738,7 +1738,7 @@ static void cik_select_se_sh(struct radeon_device *rdev,
 	u32 data = INSTANCE_BROADCAST_WRITES;
 
 	if ((se_num == 0xffffffff) && (sh_num == 0xffffffff))
-		data = SH_BROADCAST_WRITES | SE_BROADCAST_WRITES;
+		data |= SH_BROADCAST_WRITES | SE_BROADCAST_WRITES;
 	else if (se_num == 0xffffffff)
 		data |= SE_BROADCAST_WRITES | SH_INDEX(sh_num);
 	else if (sh_num == 0xffffffff)