[Skiboot] skiboot-5.3.x branched, master now open for new things!

[Stewart Smith]

Since I've tagged 5.3.0, I've also created a skiboot-5.3.x branch.

It's the new stable.

I expect to stop doing skiboot 5.2.x releases sometime soon, and stick
to 5.1.x (as it's in an IBM product) and 5.3.x releases.

If somebody cares about 5.2.x enough to maintain a stable tree, speak up
now!

For skiboot master, I'm now looking at all the outstanding goodness in
patchwork.
-- 
Stewart Smith
OPAL Architect, IBM.