The driver defined its own PCI id constants.  Kill the majority,
which were redundant, and move the rest to include/linux/pci_ids.h.

Also, move open-coded tests for "new ICH" audio chips to a single
helper function.  These tests were being patched with each new
ICH motherboard from Intel, resulting in each new PCI id being added
to several places in the driver.

Note that, even though this should be a harmless patch, there
exists the remote possibility that I mis-matched some of the
PCI ids, as I only tested ICH5.