Documentation: arm: stm32: move to rst format

This patch rewrites stm32 documentation to rst
(ReStructuredText) format.

Signed-off-by: Ludovic Barre <ludovic.barre@st.com>
Signed-off-by: Alexandre Torgue <alexandre.torgue@st.com>

Documentation/arm/stm32/stm32h743-overview.rst

@@ -0,0 +1,34 @@
+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 (STM32H743_).
+
+.. _STM32H743: http://www.st.com/en/microcontrollers/stm32h7x3.html?querycriteria=productId=LN2033
+
+:Authors:
+
+Alexandre Torgue <alexandre.torgue@st.com>