ARM: S3C64XX: Prototype SPI devices

Avoids build warnings due to the undeclared non-statics.
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Kukjin Kim <kgene.kim@samsung.com>

arch/arm/mach-s3c64xx/dev-spi.c

@@ -22,6 +22,7 @@
 
 #include <plat/s3c64xx-spi.h>
 #include <plat/gpio-cfg.h>
+#include <plat/devs.h>
 
 static char *spi_src_clks[] = {
 	[S3C64XX_SPI_SRCCLK_PCLK] = "pclk",