[SCSI] scsi_dh: Provide set_params interface in emc device handler

[SCSI] scsi_dh: Provide set_params interface in emc device handler

Handle the parameters provided by user thru multipath.

This handler expects only 2 parameters and their value can either be 0 or 1.

This code originates from the old dm-emc.c file. Appropriate changes have
been made to make it work in the new design.

Reported-by: Eddie Williams <[email protected]>
Signed-off-by: Chandra Seetharaman <[email protected]>
Tested-by: Eddie Williams <[email protected]>
Signed-off-by: James Bottomley <[email protected]>
Signed-off-by: James Bottomley <[email protected]>