[IA64] update HP CSR space discovery via ACPI

Get rid of the manual search of _CRS, in favor of
acpi_get_vendor_resource() which is now provided by the ACPI CA.  And fall
back to searching for a consumer-only address space descriptor if no
vendor-defined resource is found.

Signed-off-by: Bjorn Helgaas <bjorn.helgaas@hp.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>