hwmon: (i5k_amb) Drop i5k_channel_pci_id

Function i5k_channel_pci_id looks like it can fail, while a better
code design would make it more obvious that it can't. We can even get
rid of the function.

Signed-off-by: Jean Delvare <khali@linux-fr.org>
Acked-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: Guenter Roeck <guenter.roeck@ericsson.com>