Since

commit 890880dd
Author: Paul Kocialkowski <paul.kocialkowski@bootlin.com>
Date:   Fri Jan 4 09:56:10 2019 +0100

    drm: Auto-set allow_fb_modifiers when given modifiers at plane init

this is done automatically as part of plane init, if drivers set the
modifier list correctly. Which is the case here for both komeda and
malidp.
Acked-by: Liviu Dudau <liviu.dudau@arm.com>
Reviewed-by: Lyude Paul <lyude@redhat.com>
Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
Cc: "James (Qian) Wang" <james.qian.wang@arm.com>
Cc: Liviu Dudau <liviu.dudau@arm.com>
Cc: Mihail Atanassov <mihail.atanassov@arm.com>
Cc: Brian Starkey <brian.starkey@arm.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20210427092018.832258-1-daniel.vetter@ffwll.ch