arm64: defconfig: Enable Tegra210 support

Enable support for this new generation of the Tegra SoC.
Signed-off-by: NThierry Reding <treding@nvidia.com>

arch/arm64/configs/defconfig

@@ -42,6 +42,7 @@ CONFIG_ARCH_SEATTLE=y
 CONFIG_ARCH_STRATIX10=y
 CONFIG_ARCH_TEGRA=y
 CONFIG_ARCH_TEGRA_132_SOC=y
+CONFIG_ARCH_TEGRA_210_SOC=y
 CONFIG_ARCH_QCOM=y
 CONFIG_ARCH_SPRD=y
 CONFIG_ARCH_THUNDER=y