Network: Add an IPv4 configuration option.  Hardcoded to =y for now, but I would like to be able to select IPv4 and/or IPv6 in the future

This is not the official configuration for the PX4 board and has led to confusion by NuttX users.  The board configuration also requires some ongoing maintenance and customization to support ongoing PX4 testing and evaluation.  It is best retained the PX4 repositories where it can be properly maintained and not in the upstream NuttX repository.

Removed setting of the initial timer interval load value (or, rather, it is always set to zero for a free-running timer).  Also, do not unconditional enable the timer out interrupt.  The timerout interrupt is not not enabled until tiva_timer32_setinterval() is called.

Timer Timer:  Timer driver now initializes without complaints.  Need a test driver of some kind to make more testing progress.

Tive System Control: Add logic to configure the alternatie clock source (ALTCLK).  Needed by the Tiva timer module

DK-TM42129X: Support for the TMP100 temperature sensor is enabled by default in the NSH configuration

Tiva PHY Interrupts: Need to read the PHY interrupt status register in order to clear the pending PHY interrupt

stm32f429i-disco: change ltdc initializing during boot up. This moves initializing of the ili9341 lcd and ltdc driver to the board specific initializing routine.

Signed-off-by: Marco Krahl <ocram.lhark@gmail.com>

STM32F429i-Disco USB:  Strangeness: Conditioned on OTGHS but called otgfs initialize routines.  Must be something broken

Tiva SSI: Fix some recent breakage to the Tiva SSI driver for the case where only one SSI modules is enabled