New automaton based, secure, fully independent STM32F4 bootloader

(HEAD -> master, tag: v1.0.0, m/master, github/master) Merge branch 'master' of https://github.com/wookey-project/bootloader
[bugfix] add missing include for reboot on panic mode
(github/reboot) [bugfix] add missing include for reboot on panic mode
[bugfix] release all devices (GPIOs, USART), clear RCC clocks, before booting kernel
[bugfix] typos
[update] updated loader usart handling to support its own usart configuration
[bugfix] using SPRMOD field only for compatible SoCs
[enhancement] add support for bootloader code & bootinfo writelock
Merge pull request #6 from PThierry/self_protection
(pthierry/self_protection, self_protection) [enhancement] make automaton resilient to bit flip attack
(portable_boot) [bugfix] make CRC calculation global to all platforms. Protect err label for integrity check
[bugfix] made DFU support limited to Wookey boards only
[enhancement] transition-centric automaton based bootloader rewriting
Merge pull request #4 from arnauldm/ami/serial
Merge pull request #3 from PThierry/portable_boot
[enhancement] Cleaner serial management by the kernel for debugging purpose
(pthierry/portable_boot) [enhancement] updated DFU button GPIO config handling to support various boards. Though not layout based by now

Fully autonomous STM32 bootloader sources

The bootloader does not rely anymore on the EwoK kernel BSP C code. This patch includes the following:

• all requested arch-specific files (including SoC and core specific implementations)
• a poll-based button pushed detection. This permits to delete EXTI support from the bootloader, reducing the amount of code and the security impact of handling external interrupts

The bootloader also supports fully automated CI integration using travis, through disco407 and wookey build check for both master commits and PR

Initial public complete bootloader release

This is the initial public release of the bootloader.
This release include a (not-yet standalone) bootloader implementation for STM32F4 SoCs, including:

• STM32F429
• STM32F407
• STM32F439

These SoCs can be used in ST Doscovery evaluation boards