[PATCH] libata: use correct map_db values for ICH8

Use valid values for ICH8 map_db.  With the old values, when the
controller was in Native mode, and SCC was 1 (drives configured for
IDE), any drive plugged into a slave port was not recognized.  For
Combined Mode (and SCC is still 1), 2 is a value value for MAP.map_value,
and needs to be recognized.

Signed-off-by: Kristen Carlson Accardi <kristen.c.accardi@intel.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>