arm64: defconfig: Enable Tegra186 timer support

Enable Tegra186 timer support which is needed for Tegra186, Tegra194 and
Tegra234 devices.
Signed-off-by: Jon Hunter <jonathanh@nvidia.com>
Signed-off-by: Thierry Reding <treding@nvidia.com>

arch/arm64/configs/defconfig

@@ -1006,6 +1006,7 @@ CONFIG_RTC_DRV_SNVS=m
 CONFIG_RTC_DRV_IMX_SC=m
 CONFIG_RTC_DRV_MT6397=m
 CONFIG_RTC_DRV_XGENE=y
+CONFIG_TEGRA186_TIMER=y
 CONFIG_DMADEVICES=y
 CONFIG_DMA_BCM2835=y
 CONFIG_DMA_SUN6I=m