spi: cadence: Add dependency on ARM

Add dependency on ARM in Kconfig.
This is to fix the build error related to _relaxed IO.
Remove dependency on SPI_MASTER because this is already defined
under if SPI_MASTER in Kconfig.
Signed-off-by: Harini Katakam <harinik@xilinx.com>
Signed-off-by: Mark Brown <broonie@linaro.org>

drivers/spi/Kconfig

@@ -150,7 +150,7 @@ config SPI_BUTTERFLY
 
 config SPI_CADENCE
 	tristate "Cadence SPI controller"
-	depends on SPI_MASTER
+	depends on ARM
 	help
 	  This selects the Cadence SPI controller master driver
 	  used by Xilinx Zynq.