Allow VM to read sysfs PCI config, revision files

Allow VM to read sysfs PCI config, revision files

This fixes a blank screen when viewing a VM with virtio graphics and
gl-accelerated Spice display on Ubuntu 22.04 / libvirt 8.0.0 / qemu 6.2.

Without these AppArmor permissions, the libvirt error log contains
repetitions of:

qemu_spice_gl_scanout_texture: failed to get fd for texture

This appears to be similar to this GNOME Boxes issue:
https://gitlab.gnome.org/GNOME/gnome-boxes/-/issues/586

Fixes: https://launchpad.net/bugs/1972075
Signed-off-by: Max Goodhart <c@chromakode.com>
Reviewed-by: Christian Ehrhardt <christian.ehrhardt@canonical.com>