ahci: request all PCI BARs

ahci is often implemented with accompanying SFF compatible interface
and legacy IDE driver may attach to the legacy IO ports when the
controller is already claimed by ahci and vice-versa.  This patch
makes ahci use pcim_iomap_regions_request_all() so that all IO regions
are claimed on attach.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>