drm/radeon: don't mess with hot plug detect for eDP or LVDS connector v2

It seems imac pannel doesn't like whe we change the hot plug setup
and then refuse to work. This help but doesn't fully fix:
https://bugzilla.redhat.com/show_bug.cgi?id=726143

v2: fix typo and improve commit message
Signed-off-by: Matthew Garrett <mjg@redhat.com>
Signed-off-by: Jerome Glisse <jglisse@redhat.com>
Reviewed-by: Alex Deucher <alexander.deucher@amd.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>

drivers/gpu/drm/radeon/r600.c

@@ -713,6 +713,14 @@ void r600_hpd_init(struct radeon_device *rdev)
 	list_for_each_entry(connector, &dev->mode_config.connector_list, head) {
 		struct radeon_connector *radeon_connector = to_radeon_connector(connector);
 
+		if (connector->connector_type == DRM_MODE_CONNECTOR_eDP ||
+		    connector->connector_type == DRM_MODE_CONNECTOR_LVDS) {
+			/* don't try to enable hpd on eDP or LVDS avoid breaking the
+			 * aux dp channel on imac and help (but not completely fix)
+			 * https://bugzilla.redhat.com/show_bug.cgi?id=726143
+			 */
+			continue;
+		}
 		if (ASIC_IS_DCE3(rdev)) {
 			u32 tmp = DC_HPDx_CONNECTION_TIMER(0x9c4) | DC_HPDx_RX_INT_TIMER(0xfa);
 			if (ASIC_IS_DCE32(rdev))