UPSTREAM: kvm: nVMX: Allow L1 to intercept software exceptions (#BP and #OF)

When L2 exits to L0 due to "exception or NMI", software exceptions
(#BP and #OF) for which L1 has requested an intercept should be
handled by L1 rather than L0. Previously, only hardware exceptions
were forwarded to L1.

BUG=chromium:677993
TEST=Build and test

Change-Id: I9e49aece3ffbbbe3353a55b17c2f04d89d7c16aa
Signed-off-by: Jim Mattson <jmattson@google.com>
Cc: stable@vger.kernel.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Guenter Roeck <groeck@chromium.org>
(cherry picked from commit ef85b6738543)
Reviewed-on: https://chromium-review.googlesource.com/424438
Reviewed-by: Dmitry Torokhov <dtor@chromium.org>
(cherry picked from commit 1422087cd02306b962805e6cbb3709677bb0fe87)
Reviewed-on: https://chromium-review.googlesource.com/428897