drm/xe: Support for I2C attached MCUs

drm/xe: Support for I2C attached MCUs

Adding adaption/glue layer where the I2C host adapter
(Synopsys DesignWare I2C adapter) and the I2C clients (the
microcontroller units) are enumerated.

The microcontroller units (MCU) that are attached to the GPU
depend on the OEM. The initially supported MCU will be the
Add-In Management Controller (AMC).

Co-developed-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Michael J. Ruhl <michael.j.ruhl@intel.com>
Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Reviewed-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Reviewed-by: Andi Shyti <andi.shyti@linux.intel.com>
Link: https://lore.kernel.org/r/20250701122252.2590230-4-heikki.krogerus@linux.intel.com
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
[Rodrigo fixed the co-developed tags and SPDX format in the .c file]