media: cadence: csi2rx: Add wrappers for subdev calls

When this bridge driver is being user by another platform driver, it
might want to call subdev operations like getting format, setting
format, enumerating format codes, etc. Add wrapper functions that pass
that call through to the sensor.

Currently wrappers are added only for the ops used by TI's platform
driver. More can be added later as needed.

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