S3 resume sometimes hangs up the GPU / etnaviv
Feature: https://source.puri.sm/Librem5/use-cases/issues/75
when resuming from suspend, I sometimes get:
[ 1265.539186] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1266.179170] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1266.819181] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1267.459696] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1268.099711] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1270.499717] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1271.139698] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1271.779167] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1272.419174] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1273.059167] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1273.699711] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1274.339157] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1274.979149] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1278.499174] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1279.139169] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1279.779173] etnaviv-gpu 38000000.gpu: recover hung GPU!
[ 1280.419678] etnaviv-gpu 38000000.gpu: recover hung GPU!