Pcie: Bind hotplug vfio pci device into vfio-pci-pm driver first
Pcie: Bind hotplug vfio pci device into vfio-pci-pm driver first

This commit use the same logic as in initramfs, let hotplug vfio
pci device bind to vfio-pci-pm driver first, if it fails, then
bind to vfio-pci driver.

Without this, there are error message about hotplug vfio pci device's
pm_ops.

BUG=None
TEST=Check hotplug vfio pci device's driver in hypervisor

Change-Id: I8330c7859dff2b8b2db1baa67c16181e2de66ae1
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/crosvm/+/3595227
Reviewed-by: Micah Morton <68552800bc861ffdf214ff67711f32ef035ab9f6@chromium.org>
Commit-Queue: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>
Tested-by: kokoro <2ac7b1f3fa578934c95181d4272be0d3bca00121@google.com>
Reviewed-by: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm