vfio: extract setup logic out of resource mapping
vfio: extract setup logic out of resource mapping

The setup logic access the global vfio_cfg variable that will be moved in the
following commits. We need to separate all accesses to this variable to a
general code.

Signed-off-by: Jan Viktorin <077cce75738556d99b8362c6a64d5bba1ba87459@rehivetech.com>

john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk,john-mcnamara-intel/dpdk