[U-Boot] U-Boot test failures; rebase on master

[Stephen Warren]

The following U-Boot repos have recently rebased on u-boot.git master 
branch, and picked up some changes that cause test failures on one/both 
of NVIDIA Jetson TX2 and sandbox. That potentially prevents any testing 
from finding any additional issues that are introduced in these repos. 
If you rebase on the latest u-boot.git master branch you'll pick up 
fixes that solve these failures, and make all of test/py pass on all the 
boards I test...

u-boot-usb.git master
u-boot-video.git master
u-boot-dfu.git master
u-boot-spi.git master

Thanks!