ARM: spitz: Use software nodes to describe SPI CS lines

ARM: spitz: Use software nodes to describe SPI CS lines

Convert the Spitz to use software nodes for specifying SPI CS. Because
the SPI core can figure out the number of chipselects from the number
of GPIO handles specified in properties, setting "num-cs" property is
no longer needed.

Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Link: https://lore.kernel.org/r/20240628180852.1738922-6-dmitry.torokhov@gmail.com
Signed-off-by: Arnd Bergmann <arnd@arndb.de>