CFLAGS_KERNEL is automatically added to the command line for compiling
objects which will be linked into vmlinux. (As opposed to objects which
will be in modules, where MODFLAGS is added).

AFLAGS_KERNEL was not added automatically, now it is:

AFLAGS_KERNEL is now automatically added to the command line for assembling
objects which will be linked into vmlinux.

Note: this change is a no-op for all archs except IA64, since
[AC]FLAGS_KERNEL is not used there at all.

At the same time, remove two assembling rules from two arch/ia64 
subdirectories which don't contain any assembler sources at all.

Also, add an @ in front of the ugly
	make CFLAGS=".." AFLAGS=".." -C subdir
command, make will print its "Entering directory ..." line, so 
we get that information anyway.