Do reset for passthrough PCI device by default when assigning it to post-launched
VM:
1. modify opt "reset" to "no_reset" -- could enable no_reset for debug only
2. remove "ptdev_no_reset" opt. It could be replaced by setting "no_reset" for
each passthrough device.
Tracked-On: #3465
Signed-off-by: Li Fei1 <fei1.li@intel.com>
Acked-by: Yu Wang <yu1.wang@intel.com>