Separate out ata_dev_configure() from ata_dev_identify() such that
ata_dev_configure() only configures @dev according to passed in @id.
The function now does not disable device on failure, it just returns
appropirate error code.

As this change leaves ata_dev_identify() with only reading ID, calling
configure and disabling devices according to the results, this patch
also kills ata_dev_identify() and inlines the logic into
ata_bus_probe().
Signed-off-by: Tejun Heo <htejun@gmail.com>
Signed-off-by: Jeff Garzik <jeff@garzik.org>