drm: Drop drm_get_link_status_name()

drm_get_link_status_name() isn't used so kill it.

Fixes the following sparse warning:
drm_connector.c:618:1: warning: symbol 'drm_get_link_status_name' was not declared. Should it be static?

Cc: Manasi Navare <manasi.d.navare@intel.com>
Fixes: 40ee6fbe ("drm: Add a new connector atomic property for link status")
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20170901165328.24459-3-ville.syrjala@linux.intel.com


Reviewed-by: Thierry Reding <treding@nvidia.com>