x86/cpu: Resort and comment Intel models

The INTEL_FAM6 list has become a mess again. Try and bring some sanity
back into it.

Where previously we had one microarch per year and a number of SKUs
within that, this no longer seems to be the case. We now get different
uarch names that share a 'core' design.

Add the core name starting at skylake and reorder to keep the cores
in chronological order. Furthermore, Intel marketed the names {Amber,
Coffee, Whiskey} Lake, but those are in fact steppings of Kaby Lake, add
comments for them.

Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Signed-off-by: Borislav Petkov <bp@suse.de>
Link: https://lkml.kernel.org/r/YE+HhS8i0gshHD3W@hirez.programming.kicks-ass.net