media: ti: Add CSI2RX support for J721E

TI's J721E uses the Cadence CSI2RX and DPHY peripherals to facilitate
capture over a CSI-2 bus.

The Cadence CSI2RX IP acts as a bridge between the TI specific parts and
the CSI-2 protocol parts. TI then has a wrapper on top of this bridge
called the SHIM layer. It takes in data from stream 0, repacks it, and
sends it to memory over PSI-L DMA.

This driver acts as the "front end" to V4L2 client applications. It
implements the required ioctls and buffer operations, passes the
necessary calls on to the bridge, programs the SHIM layer, and performs
DMA via the dmaengine API to finally return the data to a buffer
supplied by the application.

Signed-off-by: Pratyush Yadav <p.yadav@ti.com>
Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>