ARM: dts: ls1021a: add support for Moxa UC-8410A open platform

Add support for Moxa UC-8410A open platform

The UC-8410A computing platform is designed
for embedded communication-centric industrial applications

The features of UC-8410A are:
* QSPI flash
* SD slot
* 3x LAN
* 8x RS-232/422/485 ports, software-selectable
* Mini PCIe form factor with PCIe/USB signal
* 2x USB host
* TPM
* Watchdog
* RTC
* User LEDs
* Beeper
* Push button

Signed-off-by: Jimmy Chen <jimmy.chen@moxa.com>
Signed-off-by: Harry YJ Jhou <harryyj.jhou@moxa.com>
Signed-off-by: SZ Lin <sz.lin@moxa.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>