arm64: dts: imx: Add i.mx8mm Gateworks gw7903 dts support

The GW7903 is based on the i.MX 8M Mini SoC featuring:
 - LPDDR4 DRAM
 - eMMC FLASH
 - microSD connector with UHS support
 - LIS2DE12 3-axis accelerometer
 - Gateworks System Controller
 - IMX8M FEC
 - software selectable RS232/RS485/RS422 serial transceiver
 - PMIC
 - 2x off-board bi-directional opto-isolated digital I/O
 - 1x M.2 A-E Key Socket and 1x MiniPCIe socket with USB2.0 and PCIe
   (resistor loading to route PCIe/USB2 between M.2 and MiniPCIe socket)
Signed-off-by: Tim Harvey <tharvey@gateworks.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

arch/arm64/boot/dts/freescale/Makefile

@@ -63,6 +63,7 @@ dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw72xx-0x.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw73xx-0x.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7901.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7902.dtb
+dtb-$(CONFIG_ARCH_MXC) += imx8mm-venice-gw7903.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mm-verdin-nonwifi-dahlia.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mm-verdin-nonwifi-dev.dtb
 dtb-$(CONFIG_ARCH_MXC) += imx8mm-verdin-wifi-dahlia.dtb