u-boot-boundary: update to 4dfca8881

Update to latest commit on Boundary Devices U-Boot 2014.04 tree.

Notable updates include:
	support for a number of new boards, including Nitrogen6 Max
	fixes for boot scripts for Solo and Dual-Lite processors
	fixes to support the use of RAM disks
	additional LCD panels:
		Ampire 1024x600 (Ilitek touch)
		WVGA LVDS

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
linux-boundary (3.10.17): Bump SRCREV to 50c5697b

Updates in this release include:
        - rebase on Freescale 3.10.17_1.0.1_ga release
        - support for new (custom) boards
        - fixes for production version of Nitrogen6 Max board
        - fixes to allow shutdown/restart of WL12xx Wi-Fi
        - added support for adv7180 NTSC video input driver
        - added support for Gennum GS2971 SDI receiver
        - added Ilitek 210x touch screen driver
        - update Focaltech ft5x06 touch screen to support 12 touches
        - update flexcan driver to allow use with only a standby GPIO
        - add support for "disable_giga" parameter for FEC Gb ethernet driver
        - add support for SC16IS7XX I2C multi-port serial controller
        - add support for "TRULY-1U" display
        - add support for Wolfson WM5102 audio codec

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
nitrogen6x: Add support for Nitrogen6_Max board

The Nitrogen6_Max board differs from Nitrogen6x only in its'
device-tree and U-Boot configuration.

Add device-tree to the Nitrogen6x image build, along with the
SABRE Lite and Nitrogen6x and document U-Boot build.

Signed-off-by: Eric Nelson <eric.nelson@boundarydevices.com>
Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>