imx-common: add board_video_skip

this function is shared by several boards and thus can be factorized

Signed-off-by: Eric Bénard <eric@eukrea.com>
Acked-by: Eric Nelson <eric.nelson@boundarydevices.com>
Acked-by: Stefano Babic <sbabic@denx.de>
imx-common/video: add detect_hdmi

this function is used by several board together with board_video_skip
to detect if hdmi is plugged is order to select the display to use.
So move it in imx-common to share it.

Signed-off-by: Eric Bénard <eric@eukrea.com>
wandboard: add Future Eletronics 7" WVGA LCD extension board

This adds support for the 7" WVGA produced by Future Eletronics and
make it dynamically detect if it is connected or not based on the
touchscreen controller.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>
Acked-by: Stefano Babic <sbabic@denx.de>
wandboard: Pass video kernel arguments for HDMI and LCD

This checks if the 7" WVGA produced by Future Eletronics is detected
and pass the needed kernel arguments for it to work.

Signed-off-by: Otavio Salvador <otavio@ossystems.com.br>