[SCSI] scsi_transport_sas: remove local_attached flag

This flag denotes local attachment of the phy.  There are two problems
with it:

1) It's actually redundant ... you can get the same information simply
by seeing whether a host is the phys parent
2) we condition a lot of phy parameters on it on the false assumption
that we can only control local phys.  I'm wiring up phy resets in the
aic94xx now, and it will be able to reset non-local phys as well.

I fixed 2) by moving the local check into the reset and stats function
of the mptsas, since that seems to be the only HBA that can't
(currently) control non-local phys.

Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>