spi: sun4i: Support fifo_depth via drvdata

Support fifo_depth via drvdata instead of macro definition, this would
eventually reduce another macro definition for new SPI controller fifo
depth support addition.

Signed-off-by: Jagan Teki <jagan@amarulasolutions.com>
Reviewed-by: Andre Przywara <andre.przywara@arm.com>
1 file changed