bsp: valleyisland: add kernel config support for rtc

This patch enables the kernel config of rtc for valleyisland.

Signed-off-by: Chai, Chong Yi <chong.yi.chai@intel.com>
Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>

bsp/valleyisland/valleyisland.cfg

@@ -59,3 +59,13 @@ CONFIG_USB_GADGET=y
 CONFIG_USB_LIBCOMPOSITE=m
 CONFIG_USB_MASS_STORAGE=m
 CONFIG_NOP_USB_XCEIV=y
+
+# RTC Support
+CONFIG_RTC_CLASS=y
+CONFIG_RTC_HCTOSYS=y
+CONFIG_RTC_SYSTOHC=y
+CONFIG_RTC_HCTOSYS_DEVICE="rtc0"
+CONFIG_RTC_INTF_SYSFS=y
+CONFIG_RTC_INTF_PROC=y
+CONFIG_RTC_INTF_DEV=y
+CONFIG_RTC_DRV_CMOS=y