bhyve: enumerate UEFI firmwares
bhyve: enumerate UEFI firmwares

Extend domain capabilities XML with the information about
available UEFI firmware files. It searches in the location
that the sysutils/bhyve-firmware FreeBSD port installs
files to.

Signed-off-by: Roman Bogorodskiy <2a54bf90b2b53e2ab35ffe11dda2730a23b4aa9c@gmail.com>

olafhering/libvirt,VenkatDatta/libvirt,libvirt/libvirt,crobinso/libvirt,andreabolognani/libvirt,jfehlig/libvirt,datto/libvirt,datto/libvirt,libvirt/libvirt,crobinso/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,datto/libvirt,datto/libvirt,eskultety/libvirt,fabianfreyer/libvirt,jardasgit/libvirt,eskultety/libvirt,eskultety/libvirt,andreabolognani/libvirt,zippy2/libvirt,jfehlig/libvirt,nertpinx/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt,olafhering/libvirt,jardasgit/libvirt,andreabolognani/libvirt,jfehlig/libvirt,zippy2/libvirt,libvirt/libvirt,olafhering/libvirt,zippy2/libvirt,jardasgit/libvirt,datto/libvirt,andreabolognani/libvirt,zippy2/libvirt,eskultety/libvirt,nertpinx/libvirt,andreabolognani/libvirt,libvirt/libvirt,crobinso/libvirt,fabianfreyer/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,jfehlig/libvirt,eskultety/libvirt,crobinso/libvirt,fabianfreyer/libvirt,nertpinx/libvirt,VenkatDatta/libvirt,VenkatDatta/libvirt,jardasgit/libvirt