Add EV-iMX280-NANO-X-MB board

A simple prototyping board with one microSD port, one Ethernet port,
2 USB ports, I2C, SPI, GPIO, and UART interfaces.

Signed-off-by: Oleh Kravchenko <oleg@kaa.org.ua>
Cc: Stefano Babic <sbabic@denx.de>

configs/ev-imx280-nano-x-mb_defconfig

@@ -0,0 +1,91 @@
+CONFIG_ARCH_MX6=y
+CONFIG_ARM=y
+CONFIG_DEFAULT_DEVICE_TREE="ev-imx280-nano-x-mb"
+CONFIG_EV_IMX280_NANO_X_MB=y
+CONFIG_HUSH_PARSER=y
+CONFIG_IMX_MODULE_FUSE=y
+CONFIG_MX6ULL=y
+CONFIG_PINCTRL=y
+CONFIG_PINCTRL_IMX6=y
+CONFIG_SYS_TEXT_BASE=0x87800000
+CONFIG_TARGET_O4_IMX6ULL_NANO=y
+
+CONFIG_K4B4G1646D_BCMA=y
+# CONFIG_MT41K256M16HA_125E is not set
+
+# Device Tree
+CONFIG_OF_CONTROL=y
+CONFIG_OF_LIBFDT_OVERLAY=y
+
+# Environment
+CONFIG_ENV_FAT_DEVICE_AND_PART="0:1"
+CONFIG_ENV_IS_IN_FAT=y
+CONFIG_ENV_VARS_UBOOT_RUNTIME_CONFIG=y
+
+# Clock driver for imx6ull is not implemented
+# CONFIG_CLK_IMX6Q=y
+
+# Thermal
+CONFIG_DM_THERMAL=y
+CONFIG_IMX_THERMAL=y
+
+# Serial
+CONFIG_DM_SERIAL=y
+CONFIG_MXC_UART=y
+
+# eMMC support
+CONFIG_CMD_MMC=y
+CONFIG_DM_MMC=y
+CONFIG_FSL_USDHC=y
+CONFIG_SUPPORT_EMMC_BOOT=y
+CONFIG_SUPPORT_EMMC_RPMB=y
+
+# GPIO support
+CONFIG_CMD_GPIO=y
+CONFIG_DM_GPIO=y
+CONFIG_MXC_GPIO=y
+
+# USB support
+CONFIG_CI_UDC=y
+CONFIG_CMD_USB=y
+CONFIG_CMD_USB_MASS_STORAGE=y
+CONFIG_DM_USB=y
+CONFIG_USB=y
+CONFIG_USB_GADGET=y
+CONFIG_USB_GADGET_DOWNLOAD=y
+
+# Fastboot support
+CONFIG_CMD_FASTBOOT=y
+CONFIG_FASTBOOT_BUF_ADDR=0x82000000
+CONFIG_FASTBOOT_CMD_OEM_FORMAT=y
+CONFIG_FASTBOOT_FLASH=y
+CONFIG_FASTBOOT_FLASH_MMC_DEV=0
+CONFIG_USB_FUNCTION_FASTBOOT=y
+
+# Ethernet support
+CONFIG_CMD_DHCP=y
+CONFIG_CMD_MDIO=y
+CONFIG_CMD_MII=y
+CONFIG_CMD_PING=y
+CONFIG_DM_ETH=y
+CONFIG_FEC_MXC=y
+CONFIG_MII=y
+CONFIG_NET_RANDOM_ETHADDR=y
+CONFIG_PHYLIB=y
+CONFIG_PHY_SMSC=y
+
+# Watchdog support is broken
+# CONFIG_CMD_WDT=y
+# CONFIG_IMX_WATCHDOG=y
+# CONFIG_SYSRESET_WATCHDOG=y
+# CONFIG_WATCHDOG_RESET_DISABLE=y
+# CONFIG_WDT=y
+
+# misc
+CONFIG_CMD_BOOTZ=y
+CONFIG_CMD_EXT4=y
+CONFIG_CMD_FAT=y
+CONFIG_CMD_GPT=y
+CONFIG_CMD_MEMINFO=y
+CONFIG_CMD_MEMTEST=y
+CONFIG_CMD_PART=y