iio: light: bd27008: Support BD27010 RGB

The ROHM BU27010 is an RGBC sensor with a flickering detection FIFO. The
RGBC+IR sensor functionality is largely similar to what the BU27008 has.
There are some notable things though:
  - gain setting is once again new and exotic. Now, there is 6bit gain
    setting where 4 of the bits are common to all channels and 2 bits
    can be configured separately for each channel. The BU27010 has
    similar "1X on other channels vs 2X on IR when selector is 0x0"
    gain design as BU27008 had. So, we use same gain setting policy for
    BU27010 as we did for BU27008 - driver sets same gain selector for all
    channels but shows the gains separately for all channels so users
    can (at least in theory) detect this 1X vs 2X madness...
  - BU27010 has suffled all the control register bitfields to new
    addresses and bit positions while still keeping the register naming
    same.
  - Some more power/reset control is added.
  - FIFO for "flickering detection" is added.

The control register suffling made this slightly nasty. Still, it is
easier for maintenance perspective to add the BU27010 support in BU27008
driver because - even though the bit positions/addresses were changed -
most of the driver structure can be re-used. Writing own driver for
BU27010 would mean plenty of duplicate code albeit a tad more clarity.

The flickering FIFO is not supported by the driver.

Add BU27010 RGBC+IR support to rohm-bu27008 driver.

Signed-off-by: Matti Vaittinen <mazziesaccount@gmail.com>
Link: https://lore.kernel.org/r/111cd217ccece1c1f16ab4287532dc4e1ddb8a3f.1690958450.git.mazziesaccount@gmail.com


Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>