media: destage Hantro VPU driver

The Hantro mainline driver has been used in production
since several years and was only kept as a staging driver
due the stateless CODEC controls.

Now that all the stateless CODEC controls have been moved
out of staging, graduate the driver as well.

Signed-off-by: Ezequiel Garcia <ezequiel@vanguardiasur.com.ar>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>
Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>