[U-Boot] [ANN] U-Boot v2018.03-rc4 released

Hey all,

It's release day and I've released v2018.03-rc4. I've included a few different regression fixes I've seen along with some fixes and cleanups. I would like to do the release on March 12th, and likely will so long as no big regressions show up. I am worried about the RPi3 issue I've seen reported. Are there any other issues people know of currently?

And to repeat myself again, boards and SoC families, etc, that have been orphaned for more than a year should probably get dropped. I've contacted a few people off-list (which is why we've had a few pickups of late) for things, but if you know someone that would be interested in something, please speak up.

Thanks all!