Provide a user defined callback context for irq's, such that when
registering a callback users can provide a pointer that will get
passed back when the isr is called.

SAM3/4: GPIO bit numbering typo fixes.

Approved-by: Gregory Nutt

Add basic support for the STM32F334 and Nucleo F334R8 board

Approved-by: Gregory Nutt

Kinetis:  Resolve issue with duplicate definitions of up_putc.  Addition conditional logic to pick just one.

Kinetis:Add LPUART

Approved-by: Gregory Nutt

   Pin out LPUART0 for testing
   Define BOARD_SOPT2_PLLFLLSEL ti select MCGPLLCLK
   Define BOARD_SIM_CLKDIV3_FREQ etal to provide BOARD_LPUART0_FREQ

  HAVE_SERIAL_CONSOLE -> HAVE_UART_CONSOLE to bew consistent with
  HAVE_LPUART_CONSOLE naming