ath5k: Fix modinfo does not list alias -> pci-id lines

The AHB bus support patchset moved the table "Known PCI ids" from base.c
to pci.c - unfortunately, MODULE_DEVICE_TABLE() was not transferred.
With this fix 'modinfo ath5k' lists the alias -> pci-id lines, again.

The issue was introduced by:
   commit e5b046d8
   "ath5k: Move PCI bus functions to separate file."

Signed-off-by: Sedat Dilek <sedat.dilek@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>