virt module: Allow NVRAM unlinking on DOM undefine
virt module: Allow NVRAM unlinking on DOM undefine

UEFI-enabled VMs usually have pflash (NVRAM) devices attached,
which require one additional libvirt flag to be passed at 'undefine'.

This is usually the case for AArch64 (arm64) VMs, where AAVMF (AA64
UEFI) is the only supported guest bootloader.

Signed-off-by: Alexandru Avadanii <046230ef61405fd997a5cbd7cfcbca66da78c41e@enea.com>

saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt,saltstack/salt