GPIO refactoring for STM32L0
Fixes for IPCR register name
support GPIO_COUNT for STM32L0
Add GPIO support for STM32L0, fixes for F2/F4
STM32LO power support, some fixes for F2/F4
core driver implementation for STM32L0 (gpio, power)
STM32L0 timer support
startup support for Cortex-M0
Fix STM32L0 core speed detection
STM32L0 fixes
template update for HSE bypass support
add some STM32L0 examples
some STM32F1 examples: GPIO, UART, DAC, Temp, WDT, USB (CDC)
update config for example