[PATCH] sata_sil24: reimplement hardreset

Reimplement hardreset according to the datasheet.  The old hardreset
didn't reset controller status and the controller might not be ready
after reset.  Also, as SStatus is a bit flakey after hardreset,
sata_std_hardrset() didn't use to wait long enough before proceeding.

Note that as we're not depending on SStatus, DET==1 condition cannot
be used to wait for link, so use shorter timeout for no device case.

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