libata-acpi: s/CONFIG_SATA_ACPI/CONFIG_ATA_ACPI/

ACPI applies to both SATA and PATA.  Drop the 'S' from the config
variable.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>