PCI: Speed up device reset function

For all devices need to do function level reset, currently we need wait for
at least 200ms, which can be too long if we have lots of devices...

The patch checked pending bit before msleep() to skip some unnecessary
sleeping interval.

Signed-off-by: Sheng Yang <sheng@linux.intel.com>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>