x86: Relegate CONFIG_PAT and CONFIG_MTRR configurability to EMBEDDED

MTRR and PAT support (which got added to CPUs over 10 years ago)
are no longer really optional in that more and more things are
depending on PAT just working, including various drivers and newer
versions of X.  (to not even speak of MTRR)

Having this as a regular config option just no longer makes sense.

This patch relegates CONFIG_X86_PAT to the EMBEDDED category so
ultra-embedded can still disable it if they really need to.

Also-Suggested-by: Roland Dreier <rdreier@cisco.com>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Henrique de Moraes Holschuh <hmh@hmh.eng.br>
LKML-Reference: <20091011103302.62bded41@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>