spi: Add spi-s3c64xx driver dependency on ARCH_EXYNOS4

The spi-s3c64xx driver is also used on Exynos4 so update the dependency
to enable build on those platforms.
Signed-off-by: Sylwester Nawrocki <s.nawrocki@samsung.com>
Signed-off-by: Kyungmin Park <kyungmin.park@samsung.com>
[grant.likely: relax depends to ARCH_EXYNOS instead of ARCH_EXYNOS4]
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>

drivers/spi/Kconfig

@@ -299,7 +299,7 @@ config SPI_S3C24XX_FIQ
 
 config SPI_S3C64XX
 	tristate "Samsung S3C64XX series type SPI"
-	depends on (ARCH_S3C64XX || ARCH_S5P64X0)
+	depends on (ARCH_S3C64XX || ARCH_S5P64X0 || ARCH_EXYNOS)
 	select S3C64XX_DMA if ARCH_S3C64XX
 	help
 	  SPI driver for Samsung S3C64XX and newer SoCs.