ARM: dts: stm32: Add DH Electronics DHCOM SoM and PDK2 board

Add support for DH Electronics DHCOM SoM and PDK2 rev. 400 carrier
board. This is an SoM with STM32MP15xx and an evaluation kit. The
baseboard provides Ethernet, UART, USB, CAN and optional display.

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Patrick Delaunay <patrick.delaunay@st.com>
Cc: Patrice Chotard <patrice.chotard@st.com>
Reviewed-by: Patrick Delaunay <patrick.delaunay@st.com>
diff --git a/board/dhelectronics/dh_stm32mp1/Kconfig b/board/dhelectronics/dh_stm32mp1/Kconfig
new file mode 100644
index 0000000..8eab986
--- /dev/null
+++ b/board/dhelectronics/dh_stm32mp1/Kconfig
@@ -0,0 +1,21 @@
+if TARGET_DH_STM32MP1_PDK2
+
+config SYS_BOARD
+	default "dh_stm32mp1"
+
+config SYS_VENDOR
+	default "dhelectronics"
+
+config SYS_CONFIG_NAME
+	default "stm32mp1"
+
+config ENV_SECT_SIZE
+	default 0x10000 if ENV_IS_IN_SPI_FLASH
+
+config ENV_OFFSET
+	default 0x1E0000 if ENV_IS_IN_SPI_FLASH
+
+config ENV_OFFSET_REDUND
+	default 0x1F0000 if ENV_IS_IN_SPI_FLASH
+
+endif