OMAP4: Panda: Add usb peripheral boot

Stripped down fastboot protocol for now but could be
just about anything.  Will revisit once a fastboot
or dfu implementation hits upstream.

Signed-off-by: John Rigby <john.rigby@linaro.org>

Conflicts:
	arch/arm/cpu/armv7/omap-common/Makefile
	arch/arm/include/asm/omap_common.h
	common/spl/spl.c
	include/configs/omap4_common.h
	spl/Makefile
15 files changed