ARM: stm32: Add a new SOC - STM32H743

The STM32H743 is a Cortex-M7 MCU running at 400MHz and containing 1MBytes
internal RAM.
Signed-off-by: Alexandre TORGUE <alexandre.torgue@st.com>

Documentation/arm/stm32/stm32h743-overview.txt

+			STM32H743 Overview
+			==================
+
+  Introduction
+  ------------
+	The STM32H743 is a Cortex-M7 MCU aimed at various applications.
+	It features:
+	- Cortex-M7 core running up to @400MHz
+	- 2MB internal flash, 1MBytes internal RAM
+	- FMC controller to connect SDRAM, NOR and NAND memories
+	- Dual mode QSPI
+	- SD/MMC/SDIO support
+	- Ethernet controller
+	- USB OTFG FS & HS controllers
+	- I2C, SPI, CAN busses support
+	- Several 16 & 32 bits general purpose timers
+	- Serial Audio interface
+	- LCD controller
+	- HDMI-CEC
+	- SPDIFRX
+	- DFSDM
+
+  Resources
+  ---------
+	Datasheet and reference manual are publicly available on ST website:
+	- http://www.st.com/en/microcontrollers/stm32h7x3.html?querycriteria=productId=LN2033
+
+  Document Author
+  ---------------
+	Alexandre Torgue <alexandre.torgue@st.com>

arch/arm/mach-stm32/board-dt.c

@@ -12,6 +12,7 @@ static const char *const stm32_compat[] __initconst = {
 	"st,stm32f429",
 	"st,stm32f469",
 	"st,stm32f746",
+	"st,stm32h743",
 	NULL
 };