When using DPDK PCI support via VFIO, the PCI device is reset
immediately before calling the PCI driver's init function. In some
cases, the device seems to not be ready to handle MMIO accesses right
away. Until the cause of this issue is fully understood, add a 500 ms
sleep as a workaround.
Change-Id: Ic893080a6f34d57eee80df3e6aa68c220c08df3e
Signed-off-by: Daniel Verkamp <daniel.verkamp@intel.com>