This is a list of things that need to be done to get this driver out of the
staging directory.

- ABI headers cleanup
  Cleanup the firmware ABI headers

- Add metadata capture support
  The IPU7 hardware should support metadata capture, but it is not
  fully verified with IPU7 firmware ABI so far, need to add the metadata
  capture support.

- Refine CSI2 PHY code
  Refine the ipu7-isys-csi2-phy.c, move the hardware specific variant
  into structure, clarify and explain the PHY registers to make it more
  readable.

- Work with the common IPU module
  Sakari commented much of the driver code is the same than the IPU6 driver.
  IPU7 driver is expected to work with the common IPU module in future.

- Register definition cleanup
  Cleanup the register definitions - remove some unnecessary definitions
  remove 'U' suffix for hexadecimal and decimal values and add IPU7 prefix
  for IPU7 specific registers.
  Some ISYS IO sub-blocks register definitions are offset values from
  specific sub-block base, but it is not clear and well suited for driver
  to use, need to update the register definitions to make it more clear
  and readable.