x86: Introduce pci_map_biosrom()

The isci driver needs to retrieve its preboot OROM image which contains
necessary runtime parameters like platform specific sas addresses and
phy configuration.  There is no ROM BAR associated with this area,
instead we will need to scan legacy expansion ROM space.

1/ Promote the probe_roms_32 implementation to x86-64
2/ Add a facility to find and map an adapter rom by pci device (according to
   PCI Firmware Specification Revision 3.0)

Signed-off-by: Dave Jiang <dave.jiang@intel.com>
LKML-Reference: <20110308183226.6246.90354.stgit@localhost6.localdomain6>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: H. Peter Anvin <hpa@linux.intel.com>