Avoton AHCI occasionally sees drive probe timeouts at driver load time.
When this happens SCR_STATUS indicates device detected, but no D2H FIS
reception. Reset the internal link state machines by bouncing
port-enable in the PCS register when this occurs.
Cc: <stable@vger.kernel.org> Signed-off-by: Dan Williams <dan.j.williams@intel.com> Signed-off-by: Tejun Heo <tj@kernel.org>