arm64: dts: imx8mm: Enable Hantro G1 and G2 video decoders

There are two decoders on the i.MX8M Mini controlled by the
vpu-blk-ctrl.  The G1 supports H264 and VP8 while the
G2 support HEVC and VP9.

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