drm/omapdrm: remove _unlocked suffix in drm_gem_object_put_unlocked

Spelling out _unlocked for each and every driver is a annoying.
Especially if we consider how many drivers, do not know (or need to)
about the horror stories involving struct_mutex.

Just drop the suffix. It makes the API cleaner.

Done via the following script:

__from=drm_gem_object_put_unlocked
__to=drm_gem_object_put
for __file in $(git grep --name-only $__from); do
  sed -i  "s/$__from/$__to/g" $__file;
done

Cc: Tomi Valkeinen <tomi.valkeinen@ti.com>
Cc: David Airlie <airlied@linux.ie>
Cc: Daniel Vetter <daniel@ffwll.ch>
Signed-off-by: Emil Velikov <emil.velikov@collabora.com>
Acked-by: Sam Ravnborg <sam@ravnborg.org>
Acked-by: Thomas Zimmermann <tzimmermann@suse.de>
Link: https://patchwork.freedesktop.org/patch/msgid/20200515095118.2743122-27-emil.l.velikov@gmail.com