spi: spi-cadence: Fix SPI NO Slave Select macro definition

spi: spi-cadence: Fix SPI NO Slave Select macro definition

Fix SPI NO Slave Select macro definition, when all the SPI CS bits
are high which means no slave is selected.

Fixes: d421a4159490 ("spi: spi-cadence: Fix SPI CS gets toggling sporadically")
Signed-off-by: Sai Krishna Potthuri <lakshmi.sai.krishna.potthuri@xilinx.com>
Signed-off-by: Amit Kumar Mahapatra <amit.kumar-mahapatra@xilinx.com>
Link: https://lore.kernel.org/r/20220713164529.28444-1-amit.kumar-mahapatra@xilinx.com
Signed-off-by: Mark Brown <broonie@kernel.org>