spi/xilinx: Revert master->setup function removal
spi/xilinx: Revert master->setup function removal

master->setup() must be initialized to be able
to successfully run spi_bitbang_start()
and satisfy if/else logic there.

"spi: convert drivers to use bits_per_word_mask"
(sha1: 24778be20f87d5aadb19624fc768b3159fa43efc)

Signed-off-by: Michal Simek <b20e59da6aeb5cea6c82b021069d69f63616c55d@xilinx.com>
Signed-off-by: Mark Brown <b51b9a92386687a9ac927cebfa0f978adeb8cea5@linaro.org>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs