sched/init/nx_start.c: Add support for CONFIG_BOARD_DRIVER_INITIALIZE. If this option is selected then nx_start() will call a board-provided function board_driver_initialize() immediately after calling up_initialize().
Rename CONFIG_BOARD_INITIALIZE to CONFIG_BOARD_LATE_INITIALIZE.
Raname board_initialize() to board_late_initialize()
configs/nucleo-f207zg, configs/nucleo-f103rb: add ADC and PWM examples; arch/arm/src/stm32_adc.c: there is no DMA CFG bit for the basic IPv1 ADC
Approved-by: GregoryN <gnutt@nuttx.org>
