[U-Boot] [ANN] U-Boot v2018.07-rc2 released

Hey all,

It's a day after when I had planned to release v2018.07-rc2, but here we are. The group of patches I applied earlier in the day took a bit longer to sort out, and that means I have a few more things I had hoped to apply still left to look at. I still think at this point we should focus on Kconfig migrations, fixes and dropping code that has reached it's "update or delete" by date.

Things look on track for -rc3 on the 2nd and then release on July 9th. Thanks all!