resource/PCI: align functions now return start of resource

As suggested by Linus, align functions should return the start
of a resource, not void. An update of "res->start" is no longer
necessary.

Cc: Bjorn Helgaas <bjorn.helgaas@hp.com>
Cc: Yinghai Lu <yhlu.kernel@gmail.com>
Signed-off-by: Dominik Brodowski <linux@dominikbrodowski.net>
Signed-off-by: Jesse Barnes <jbarnes@virtuousgeek.org>