drm/arm/mali: make malidp_mw_connector_helper_funcs static

The malidp_mw_connector_helper_funcs is not referenced by name
outside of the file it is in, so make it static to avoid the
following warning:

drivers/gpu/drm/arm/malidp_mw.c:59:41: warning: symbol 'malidp_mw_connector_helper_funcs' was not declared. Should it be static?
Signed-off-by: Ben Dooks (Codethink) <ben.dooks@codethink.co.uk>
Signed-off-by: Liviu Dudau <Liviu.Dudau@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20191217115309.2133503-1-ben.dooks@codethink.co.uk

drivers/gpu/drm/arm/malidp_mw.c

@@ -56,7 +56,7 @@ malidp_mw_connector_mode_valid(struct drm_connector *connector,
 	return MODE_OK;
 }
 
-const struct drm_connector_helper_funcs malidp_mw_connector_helper_funcs = {
+static const struct drm_connector_helper_funcs malidp_mw_connector_helper_funcs = {
 	.get_modes = malidp_mw_connector_get_modes,
 	.mode_valid = malidp_mw_connector_mode_valid,
 };