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: NHarini Katakam <harinik@xilinx.com>
Signed-off-by: NMark Brown <broonie@linaro.org>