spi: pl022: Add chip-select gpio support

Add support for an optional external chip-select gpio.

Signed-off-by: Lukas Funke <lukas.funke@weidmueller.com>
Signed-off-by: Stefan Herbrechtsmeier <stefan.herbrechtsmeier@weidmueller.com>
Reviewed-by: Jagan Teki <jagan@amarulasolutions.com>
1 file changed