earlycon: Implement STM32F10x and STM32F4x support

All config of USART/UARTs is in menuconfig

Signed-off-by: Nikita 'webconn' Maslov <wkernelteam@gmail.com>
earlycon: Remove extra includes from glue-newlib.c

Signed-off-by: Nikita 'webconn' Maslov <wkernelteam@gmail.com>
Merge pull request #51 from nekromant/stm32-earlycon

earlycon: STM32 fixes and improvements