media: verisilicon: Avoid G2 bus error while decoding H.264 and HEVC

In the Linux kernel, the following vulnerability has been resolved:

media: verisilicon: Avoid G2 bus error while decoding H.264 and HEVC

For the i.MX8MQ platform, there is a hardware limitation: the g1 VPU and
g2 VPU cannot decode simultaneously; otherwise, it will cause below bus
error and produce corrupted pictures, even potentially lead to system hang.

[ 110.527986] hantro-vpu 38310000.video-codec: frame decode timed out.
[ 110.583517] hantro-vpu 38310000.video-codec: bus error detected.

Therefore, it is necessary to ensure that g1 and g2 operate alternately.
This allows for successful multi-instance decoding of H.264 and HEVC.

To achieve this, g1 and g2 share the same v4l2_m2m_dev, and then the
v4l2_m2m_dev can handle the scheduling.