[media] VPU: mediatek: support Mediatek VPU

The VPU driver for hw video codec embedded in Mediatek's MT8173 SOCs.
It is able to handle video decoding/encoding of in a range of formats.
The driver provides with VPU firmware download, memory management and
the communication interface between CPU and VPU.
For VPU initialization, it will create virtual memory for CPU access and
IOMMU address for vcodec hw device access. When a decode/encode instance
opens a device node, vpu driver will download vpu firmware to the device.
A decode/encode instant will decode/encode a frame using VPU
interface to interrupt vpu to handle decoding/encoding jobs.

Signed-off-by: Andrew-CT Chen <andrew-ct.chen@mediatek.com>
Signed-off-by: Tiffany Lin <tiffany.lin@mediatek.com>
[hans.verkuil@cisco.com: drop unnecessary ARM || ARM64 dependency]
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>

Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>