[PATCH] x86: Clean up x86 control register and MSR macros (corrected)

This patch is based on Rusty's recent cleanup of the EFLAGS-related
macros; it extends the same kind of cleanup to control registers and
MSRs.

It also unifies these between i386 and x86-64; at least with regards
to MSRs, the two had definitely gotten out of sync.

Signed-off-by: H. Peter Anvin <hpa@zytor.com>
Signed-off-by: Andi Kleen <ak@suse.de>