ARM: sunxi: Add A31 RTC driver to sunxi_defconfig

Now that we have a driver for A31's RTC, enable it
in the default sunxi config.

Signed-off-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>

arch/arm/configs/sunxi_defconfig

@@ -93,6 +93,7 @@ CONFIG_LEDS_TRIGGER_DEFAULT_ON=y
 CONFIG_RTC_CLASS=y
 # CONFIG_RTC_INTF_SYSFS is not set
 # CONFIG_RTC_INTF_PROC is not set
+CONFIG_RTC_DRV_SUN6I=y
 CONFIG_RTC_DRV_SUNXI=y
 # CONFIG_IOMMU_SUPPORT is not set
 CONFIG_PHY_SUN4I_USB=y