arm64: defconfig: Add i.MX SCU SoC info driver

This patch selects CONFIG_IMX_SCU_SOC by default to support
i.MX system controller unit SoC info driver.

Signed-off-by: Anson Huang <Anson.Huang@nxp.com>
Reviewed-by: Abel Vesa <abel.vesa@nxp.com>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>