drm/etnaviv: bump HW job limit to 4

The current limit of 2 leads to some GPU idle times, as the usual
IRQ latency leads to up to 3 jobs getting signaled at once with some
standard workloads.

A larger HW job limit might lead to slightly worse QoS, but we accept
that to not sacrifice GPU throughput in the common case.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>

drivers/gpu/drm/etnaviv/etnaviv_sched.c

@@ -24,7 +24,7 @@
 
 static int etnaviv_job_hang_limit = 0;
 module_param_named(job_hang_limit, etnaviv_job_hang_limit, int , 0444);
-static int etnaviv_hw_jobs_limit = 2;
+static int etnaviv_hw_jobs_limit = 4;
 module_param_named(hw_job_limit, etnaviv_hw_jobs_limit, int , 0444);
 
 static struct dma_fence *