drm/etnaviv: Remove drm_sched_init_args->num_rqs usage

drm/etnaviv: Remove drm_sched_init_args->num_rqs usage

Remove member no longer used by the scheduler core.

Signed-off-by: Tvrtko Ursulin <tvrtko.ursulin@igalia.com>
Cc: Lucas Stach <l.stach@pengutronix.de>
Cc: Russell King <linux+etnaviv@armlinux.org.uk>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: etnaviv@lists.freedesktop.org
Reviewed-by: Christian Gmeiner <cgmeiner@igalia.com>
Signed-off-by: Philipp Stanner <phasta@kernel.org>
Link: https://patch.msgid.link/20260417103744.76020-20-tvrtko.ursulin@igalia.com