bsh: imx8mn-smm-s2/pro: Add iMX8MN BSH SMM S2 boards

Introduce BSH SystemMaster (SMM) S2 board family, which consists of:
iMX8MN SMM S2 and iMX8MN SMM S2 PRO boards.

Add support for iMX8MN BSH SMM S2 board:

- 256 MiB DDR3 RAM
- 512MiB Nand
- USBOTG1 peripheral - fastboot.
- 100Mbit Ethernet

Add support for iMX8MN BSH SMM S2 PRO board:

- 512 MiB DDR3 RAM
- 8 GiB eMMC
- USBOTG1 peripheral - fastboot.
- 100Mbit Ethernet

Signed-off-by: Ariel D'Alessandro <ariel.dalessandro@collabora.com>
Signed-off-by: Michael Trimarchi <michael@amarulasolutions.com>
diff --git a/arch/arm/mach-imx/imx8m/Kconfig b/arch/arm/mach-imx/imx8m/Kconfig
index f564e0d..fcdcce3 100644
--- a/arch/arm/mach-imx/imx8m/Kconfig
+++ b/arch/arm/mach-imx/imx8m/Kconfig
@@ -91,6 +91,20 @@
 	select SUPPORT_SPL
 	select IMX8M_LPDDR4
 
+config TARGET_IMX8MN_BSH_SMM_S2
+	bool "imx8mn-bsh-smm-s2"
+	select BINMAN
+	select IMX8MN
+	select SUPPORT_SPL
+	select IMX8M_DDR3L
+
+config TARGET_IMX8MN_BSH_SMM_S2PRO
+	bool "imx8mn-bsh-smm-s2pro"
+	select BINMAN
+	select IMX8MN
+	select SUPPORT_SPL
+	select IMX8M_DDR3L
+
 config TARGET_IMX8MN_EVK
 	bool "imx8mn LPDDR4 EVK board"
 	select BINMAN
@@ -221,6 +235,7 @@
 source "board/advantech/imx8mp_rsb3720a1/Kconfig"
 source "board/beacon/imx8mm/Kconfig"
 source "board/beacon/imx8mn/Kconfig"
+source "board/bsh/imx8mn_smm_s2/Kconfig"
 source "board/compulab/imx8mm-cl-iot-gate/Kconfig"
 source "board/engicam/imx8mm/Kconfig"
 source "board/freescale/imx8mq_evk/Kconfig"