xend: Fix some mistakes in tools/python/xend/util/pci.py

xend: Fix some mistakes in tools/python/xend/util/pci.py

1) PCI_PM_CTRL_NO_SOFT_RESET: this is bit3 of PMCSR(Power Management
Control/Status). It should be 8. This bit means a device's capability
of not doing an internal reset across D3hot/D0.
If the bit is 1, there shall be no reset across D3hot/D0, so we should
not use it as a method to reset device.
2) When performing reset using standard FLR methods, we should sleep
at least 100ms; in current code, it's incorrect somewhere we sleep
0.2s and somewhere 0.01s.
3) In detect_dev_info(), fix a typo: PCI_EXP_TYPE_PCI_BRIDG ->
PCI_EXP_FLAGS_TYPE.
4) fix a small typo in the comment of transform_list().

Signed-off-by: Dexuan Cui <dexuan.cui@intel.com>