arm64: defconfig: Enable RTC_DRV_SNVS

i.MX8MQ needs it for RTC support.
Signed-off-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/configs/defconfig

@@ -612,6 +612,7 @@ CONFIG_RTC_DRV_PL031=y
 CONFIG_RTC_DRV_SUN6I=y
 CONFIG_RTC_DRV_ARMADA38X=y
 CONFIG_RTC_DRV_TEGRA=y
+CONFIG_RTC_DRV_SNVS=m
 CONFIG_RTC_DRV_IMX_SC=m
 CONFIG_RTC_DRV_XGENE=y
 CONFIG_DMADEVICES=y