media: Add MIPI CCI register access helper functions

The CSI2 specification specifies a standard method to access camera sensor
registers called "Camera Control Interface (CCI)".

This uses either 8 or 16 bit (big-endian wire order) register addresses
and supports 8, 16, 24 or 32 bit (big-endian wire order) register widths.

Currently a lot of Linux camera sensor drivers all have their own custom
helpers for this, often copy and pasted from other drivers.

Add a set of generic helpers for this so that all sensor drivers can
switch to a single common implementation.

These helpers take an extra optional "int *err" function parameter,
this can be used to chain a bunch of register accesses together with
only a single error check at the end, rather than needing to error
check each individual register access. The first failing call will
set the contents of err to a non 0 value and all other calls will
then become no-ops.

Link: https://lore.kernel.org/linux-media/[email protected]/

Reviewed-by: Andy Shevchenko <[email protected]>
Tested-by: Tommaso Merciai <[email protected]>
Reviewed-by: Tommaso Merciai <[email protected]>
Signed-off-by: Hans de Goede <[email protected]>
Signed-off-by: Sakari Ailus <[email protected]>
Signed-off-by: Mauro Carvalho Chehab <[email protected]>

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