board: toradex: add apalis-imx8x 2gb wb it v1.1a module support

board: toradex: add apalis-imx8x 2gb wb it v1.1a module support

This commit adds initial support for the Toradex Apalis iMX8X 2GB WB
IT V1.1A System on Module support [1].

Boot log:
U-Boot 2020.10-02940-g894aebb7e8-dirty (Oct 22 2020 - 09:43:57 +0300)
CPU:   NXP i.MX8QXP RevB A35 at 1200 MHz at 30C
DRAM:  2 GiB
MMC:   FSL_SDHC: 0, FSL_SDHC: 1
Loading Environment from MMC... OK
In:    serial@5a070000
Out:   serial@5a070000
Err:   serial@5a070000
Model: Toradex Apalis iMX8 QuadXPlus 2GB Wi-Fi / BT IT V1.1A,
Serial# 06617018
Net:   eth0: ethernet@5b040000 [PRIME]
Hit any key to stop autoboot:  0

Functionality wise the following is known to be working:
  - eMMC and MMC/SD card
  - Ethernet (*)
  - GPIOs
  - I2C

Unfortunately, there is no USB functionality for the i.MX 8QXP as of
yet.

* With the SCU FW from the latest Toradex BSP 5.0.0 (SCU FW 1.5.1)
ETH PHY encounters bring up problems after reset, this will be fixed
soon on SCU FW side.

[1] https://www.toradex.com/computer-on-modules/apalis-arm-family/nxp-imx-8x
Signed-off-by: Igor Opaniuk <igor.opaniuk@toradex.com>
Acked-by: Oleksandr Suvorov <oleksandr.suvorov@toradex.com>