[PATCH] uml: separate libc-dependent early initialization

The serial UML OS-abstraction layer patch (um/kernel dir).

This moves all systemcalls from main.c file under os-Linux dir and joins mem.c
and um_arch.c files.

Signed-off-by: Gennady Sharapov <Gennady.V.Sharapov@intel.com>
Signed-off-by: Jeff Dike <jdike@addtoit.com>
Cc: Paolo Giarrusso <blaisorblade@yahoo.it>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>