etnaviv BO interface fixes
This reverts commit 92662d08 and applies two fixes from https://lore.kernel.org/all/20220714103143.1704573-1-l.stach@pengutronix.de/#t. Other fixes required by Mesa changes from https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/14159 are already in 5.19 upstream.
Needs and is needed by Librem5/debs/mesa!15 (merged).
/cc @guido.gunther
Edited by Sebastian Krzyszkowiak