jf: add magic samsung kernel cmdline

* from GPE ML4
* left out maxcpus=2 (caused boot crashes)

Change-Id: I7679264de7185440c71f9588766c3d25b9d6db6c
jf: fix race condition at boot

Samsung's init is shit. Even Samsung knows this. So what they did was
limit the number of cpus that get to be used at boot. This helps prevent
a race condition leading to randomish boot hangs.

Need to bring these cores online later manually.

Change-Id: I3b2f2a7475977f81b1d538b0b9319b1e9e4f42f3