media: venus: Fix occasionally failures to suspend

Failure to suspend (venus_suspend_3xx) happens when the system
is fresh booted and loading venus driver. This happens once and
after reload the venus driver modules the problem disrepair.

Fix the failure by skipping the check for WFI and IDLE bits if
PC_READY is on in control status register.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>