drm/client: Look for command-line modes first

When picking a mode, first look for modes that have been specified
by the user on the kernel's command line. Only if that fails, use
the existing heuristic of picking a nearby mode from it's various
parameters.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20220511183125.14294-3-tzimmermann@suse.de