Stable inclusion request 5.4: GPU hangs fixes for etnaviv

Could you please cherry-pick these ones to Linux 5.4

Commit: f232d9ec029ce3e2543b05213e2979e01e503408 Author: Lucas Stach l.stach@xxxxxxxxxxxxxxxxx Date: Wed, 26 Feb 2020 16:27:08 +0100

Commit: d7c5782acd354bdb5ed0fa10e1e397eaed558390 Author: Andrey Grodzovsky andrey.grodzovsky@xxxxxxxxxxxxxxxxx Date: Tue, 29 Oct 2019 11:03:05 -0400

These patches fixes GPU hangs using etnaviv driver.

Regards,

Walter