arm: rmobile: silk: Add support SDHI

This adds GPIO configuration and initialization function of SDHI on Silk board

Signed-off-by: Vladimir Barinov <vladimir.barinov+renesas@cogentembedded.com>
Signed-off-by: Nobuhiro Iwamatsu <iwamatsu@nigauri.org>
diff --git a/include/configs/silk.h b/include/configs/silk.h
index 00a3158..161e0a5 100644
--- a/include/configs/silk.h
+++ b/include/configs/silk.h
@@ -101,6 +101,9 @@
 #define CONFIG_SH_MMCIF_ADDR	0xee200000
 #define CONFIG_SH_MMCIF_CLK	48000000
 
+/* SDHI */
+#define CONFIG_SH_SDHI_FREQ	97500000
+
 /* Module stop status bits */
 /* INTC-RT */
 #define CONFIG_SMSTP0_ENA	0x00400000