i.MX defconfig update for 5.5: - Enable i.MX7ULP watchdog, DA9052 touch and USB configfs support in imx_v6_v7_defconfig. - Enable newly added S32V234 SoC and its UART driver support in arm64 defconfig. - Built i.MX8QXP SCU key driver as module in arm64 defconfig. - Change AT803X Ethernet PHY driver from module to built-in, so that we can boot i.MX8MM EVK board with rootfs on NFS.