etnaviv: sync uapi header

Import the etnaviv header changes from kernel commit 05916bed1 (drm-next)

The drm_etnaviv_gem_submit structure was extended to include performance
monitor requests. Also two new ioctls got added to be able to readout
performance monitor domains and their signals.

Signed-off-by: Christian Gmeiner <christian.gmeiner@gmail.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>