spi: add support for Renesas RSPI

The SH7757 has RSPI module. This patch supports it.

Signed-off-by: Yoshihiro Shimoda <yoshihiro.shimoda.uh@renesas.com>
Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
diff --git a/drivers/spi/Kconfig b/drivers/spi/Kconfig
index 3f9a47e..7609c9c 100644
--- a/drivers/spi/Kconfig
+++ b/drivers/spi/Kconfig
@@ -279,6 +279,12 @@
 config SPI_PXA2XX_PCI
 	def_bool SPI_PXA2XX && X86_32 && PCI
 
+config SPI_RSPI
+	tristate "Renesas RSPI controller"
+	depends on SUPERH
+	help
+	  SPI driver for Renesas RSPI blocks.
+
 config SPI_S3C24XX
 	tristate "Samsung S3C24XX series SPI"
 	depends on ARCH_S3C2410 && EXPERIMENTAL