etnaviv: Make contexts track resources

etnaviv: Make contexts track resources

Currently, the screen tracks all resources for all contexts, but this
is not correct. Each context should track the resources it uses. This
also allows a context to detect whether a resource is used by another
context and to notify another context using a resource that the current
context is done using the resource.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Christian Gmeiner <christian.gmeiner@gmail.com>
Cc: Guido Günther <guido.gunther@puri.sm>
Cc: Lucas Stach <l.stach@pengutronix.de>