Squashed commit of the following:
Author: Gregory Nutt <gnutt@nuttx.org>
Many small changes related to coding style.
Author: Petro Karashchenko <petro.karashchenko@gmail.com>
configs/beaglebone-black: Adds initial support for the BeagleBone Black board.
arch/arm/src/am335x: Adds initial support for the TI AM355x family.