[SCSI] mpt2sas: Driver will use sas address instead of handle as a lookup

[SCSI] mpt2sas: Driver will use sas address instead of handle as a lookup

The device driver was not handling updating device handles in all cases
across diag resets. To fix this issue, the driver is converted to using sas
address instead of handle as a lookup reference to the parent expander or
sas_host. Also, for both expanders and sas host, the phy handle will be one
unique handle. In the sas host case, the phy handle can be different for
every phy, so the change is to set the handle to the handle of the first
phy; every phy will be one single sas address(phy 0) instead of a different
sas address for every phy(previous implementation). So making one consistent
sas address for all the direct attachedports to the sas host, will make it
better user experience when using udev /dev/disk/by-path dev nodes

Signed-off-by: Kashyap Desai <kashyap.desai@lsi.com>
Signed-off-by: Eric Moore <Eric.moore@lsi.com>
Signed-off-by: James Bottomley <James.Bottomley@suse.de>