x86/Kconfig: Clean up Kconfig defaults

The main goal here is to have the resulting .config no carry any
options that aren't enabled and can't be (i.e such where the
default is "no" and can't be changed), so that if any such
option later gets a user visible prompt, the user will actually
be prompted on a "make ...oldconfig" rather than keeping the
previously invisible option disabled.

There's a little bit of other trivial cleanup mixed in here.

Signed-off-by: Jan Beulich <jbeulich@suse.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Link: http://lkml.kernel.org/r/504DEE19020000780009A285@nat28.tlf.novell.com


Signed-off-by: Ingo Molnar <mingo@kernel.org>