board: iot2050: Support new IOT2050-SM variant

Main differences between the new variant and Advanced PG2:

1. Arduino interface is removed. Instead, an new ASIC is added for
   communicating with PLC 1200 signal modules.
2. USB 3.0 type A connector is removed, only USB 2.0 type A connector is
   available.
3. DP interface is tailored down. Instead, to communicate with the
   PLC 1200 signal modules, a USB 3.0 type B connector is added but the
   signal is not USB.
4. DDR size is increased to 4 GB.
5. Two sensors are added, one tilt sensor and one light sensor.

Signed-off-by: Baocheng Su <baocheng.su@siemens.com>
[Jan: rebased over OF_UPSTREAM]
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
diff --git a/arch/arm/dts/k3-am65-iot2050-boot-image.dtsi b/arch/arm/dts/k3-am65-iot2050-boot-image.dtsi
index 1b31d41..f49d6f2 100644
--- a/arch/arm/dts/k3-am65-iot2050-boot-image.dtsi
+++ b/arch/arm/dts/k3-am65-iot2050-boot-image.dtsi
@@ -229,7 +229,10 @@
 		};
 
 		fit@380000 {
-			fit,fdt-list-val = "ti/k3-am6528-iot2050-basic-pg2", "ti/k3-am6548-iot2050-advanced-pg2", "ti/k3-am6548-iot2050-advanced-m2";
+			fit,fdt-list-val = "ti/k3-am6528-iot2050-basic-pg2",
+					   "ti/k3-am6548-iot2050-advanced-pg2",
+					   "ti/k3-am6548-iot2050-advanced-m2",
+					   "ti/k3-am6548-iot2050-advanced-sm";
 
 			images {
 				bkey-usb3-overlay {