CHROMIUM: x86, kaiser: Allow CONFIG_KAISER and CONFIG_PARAVIRT

Kaiser may be enabled for paravirt guests not using the paravirt mmu.
Restrict the conflicts to XEN and LGUEST_GUEST.

BUG=b:69416387
TEST=trybots (lakitu, soraka, clapper)

Change-Id: I4a6308ba7ff1c636fa9b9b89a6900bbc219eef35
Reviewed-on: https://chromium-review.googlesource.com/780320
Commit-Ready: Aditya Kali <adityakali@google.com>
Tested-by: Aditya Kali <adityakali@google.com>
Reviewed-by: Aditya Kali <adityakali@google.com>
Reviewed-by: Guenter Roeck <groeck@chromium.org>
Reviewed-by: Hugh Dickins <hughd@google.com>
(cherry picked from commit da203625d9011e3d196ae9fc8b6e7c42a33ebae5)
Signed-off-by: Aditya Kali <adityakali@google.com>
Reviewed-on: https://chromium-review.googlesource.com/782383
Reviewed-by: Owen Hofmann <osh@google.com>

• security/Kconfig[diff]