media: venus: firmware: add routine to reset ARM9

Add routine to reset the ARM9 and brings it out of reset. Also
abstract the Venus CPU state handling with a new function. This
is in preparation to add PIL functionality in venus driver.

Signed-off-by: Vikash Garodia <vgarodia@codeaurora.org>
Acked-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Reviewed-by: Alexandre Courbot <acourbot@chromium.org>
Tested-by: Alexandre Courbot <acourbot@chromium.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>