[coreboot] [PATCH]Move cpu includes to cpus

[Patrick Georgi]

Hi,

attached patch moves the CPU specific includes from
src/arch/i386/Makefile.inc to the respective CPU directories.
One exception is the tyan/s2735 rule, as this is a weird situation: CAR
code for exactly one board. As soon as sibling boards are identified and
CAR enabled, it would make sense to move that include out as well. For
now, for the increased visibility (and because I'm a bit puzzled where a
good location for that file would be), I left it there.

The cpu/x86/car/cache_as_ram.lds is useless, so deleting it is also part
of this change (not tracked in this patch)

Signed-off-by: Patrick Georgi