Up until now there are just two ways how to specify UEFI paths to
libvirt. The first one is editing qemu.conf, the other is editing
qemu_conf.c and recompile which is not that fancy. So, new
configure option is introduced: --with-loader-nvram which takes a
list of pairs of UEFI firmware and NVRAM store. This way, the
compiled in defaults can be passed during compile time without
need to change the code itself.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>