dm: fpga: Introduce new uclass

dm: fpga: Introduce new uclass

For future DM based FPGA drivers and for now to have a meaningful
logging class for old FPGA drivers.

Suggested-by: Michal Simek <[email protected]>
Suggested-by: Simon Glass <[email protected]>
Signed-off-by: Alexander Dahl <[email protected]>
Reviewed-by: Simon Glass <[email protected]>
Link: https://lore.kernel.org/r/[email protected]
Signed-off-by: Michal Simek <[email protected]>