[PATCH] sata_sil24: separate out sil24_init_controller()

Separate out controller initialization from sil24_init_one() into
sil24_init_controller().  This will be used by resume.

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