Add DTSI for Variscite VAR-SOM-MX93 System on Module and DTS for Variscite
VAR-SOM-MX93 on Symphony evaluation board.

This version comes with:
- NXP i.MX 93 Dual, 1.7GHz, Cortex-A55 + Cortex-M33
- 2 GB of RAM
- 16GB eMMC
- 802.11ax/ac/a/b/g/n WiFi with 5.3 Bluetooth
- CAN bus
- Audio codec
Signed-off-by: Mathieu Othacehe <othacehe@gnu.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>