drm: Quiet down drm_mode_getconnector

Debug logging in this function does not provide any information
apart that the userspace is calling an ioctl on the connector.

There is not any info on the connector provided at all and
since there are other ioctls userspace typically calls which
do log useful things about the same connectors, remove this
one to make things a little bit more readable when KMS debugging
is turned on.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@intel.com>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: dri-devel@lists.freedesktop.org
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Link: http://patchwork.freedesktop.org/patch/msgid/1461751622-26927-10-git-send-email-tvrtko.ursulin@linux.intel.com