vmwgfx stopped using them.

With the drm device model that we've slowly evolved over the past few
years master status essentially controls access to display resources,
and nothing else. Since that's a pure access permission check drivers
should have no need at all to track additional state on a per file
basis.

Aside: For cleanup and restoring kernel-internal clients the grand
plan is to move everyone over to drm_client and
drm_master_internal_acquire/release, like the generic fbdev code
already does. That should get rid of most ->lastclose implementations,
and I think also subsumes any processing vmwgfx does in
master_set/drop.
Reviewed-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Thomas Hellstrom <thellstrom@vmware.com>
Cc: "Thomas Hellström (VMware)" <thomas_os@shipmail.org>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20200127100203.1299322-1-daniel.vetter@ffwll.ch