soc: imx: imx8m-blk-ctrl: add i.MX8MQ VPU blk-ctrl

This adds the necessary bits to drive the VPU blk-ctrl on the i.MX8MQ, to
avoid putting more of this functionality into the decoder driver.

Signed-off-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>