I/O registers that are used in early start-up stage. This replaces the
special bootstrap-time-only bus_space_map function in smdk{2410,2800}_machdep.c.
This makes SMDK{2410,2800}'s initarm() a bit simpler, and gives us smaller diffs
to other evbarm platforms.
An another good thing for SMDK2800 is that now we have all built-in peripheral
registers mapped in 2 segments. We may expect less TLB miss on I/O access
(very slightly).
but there are very small diffs in register definitions. For that, add
new options SSCOM_S3C{2800,2410,2400} and include appropriate
s3c*reg.h.
SSCOM_S3C2410 is also needed for interrupt controller differences.
christos