This trait handles the x86-specific features of an irqchip, including
getting and setting the state of the pic, ioapic, lapics, and pit.
Also includes an empty implementation of this trait for the
KvmKernelIrqChip.
BUG=chromium:1077058
TEST=cargo test -p devices
Change-Id: I36034661f4a2baedc7ac2b8f311cab6327afefba
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/2197717
Tested-by: kokoro <noreply+kokoro@google.com>
Commit-Queue: Colin Downs-Razouk <colindr@google.com>
Reviewed-by: Daniel Verkamp <dverkamp@chromium.org>
Reviewed-by: Stephen Barber <smbarber@chromium.org>
