ARM: stm32: add initial documentation for STM32MP151

This patch adds initial documentation of STM32MP151 microprocessor (MPU)
based on Arm Cortex-A7.

Signed-off-by: Roan van Dijk <roan@protonic.nl>
Signed-off-by: Alexandre Torgue <alexandre.torgue@foss.st.com>

Documentation/arm/index.rst

@@ -58,6 +58,7 @@ SoC-specific documents
    stm32/stm32f769-overview
    stm32/stm32f429-overview
    stm32/stm32mp13-overview
+   stm32/stm32mp151-overview
    stm32/stm32mp157-overview
    stm32/stm32-dma-mdma-chaining
 

Documentation/arm/stm32/stm32mp151-overview.rst

@@ -0,0 +1,36 @@
+===================
+STM32MP151 Overview
+===================
+
+Introduction
+------------
+
+The STM32MP151 is a Cortex-A MPU aimed at various applications.
+It features:
+
+- Single Cortex-A7 application core
+- Standard memories interface support
+- Standard connectivity, widely inherited from the STM32 MCU family
+- Comprehensive security support
+
+More details:
+
+- Cortex-A7 core running up to @800MHz
+- FMC controller to connect SDRAM, NOR and NAND memories
+- QSPI
+- SD/MMC/SDIO support
+- Ethernet controller
+- ADC/DAC
+- USB EHCI/OHCI controllers
+- USB OTG
+- I2C, SPI busses support
+- Several general purpose timers
+- Serial Audio interface
+- LCD-TFT controller
+- DCMIPP
+- SPDIFRX
+- DFSDM
+
+:Authors:
+
+- Roan van Dijk <roan@protonic.nl>