Fix data stage name matching issue

This fix allows the name of the stage to be specifed after the
controler and DIMM is specified.  Prior to this fix, if the
data stage name is not the first entry on the command line,
the operation is applied to all controller and DIMMs.

Signed-off-by: James Yang <James.Yang@freescale.com>
Signed-off-by: Andy Fleming <afleming@freescale.com>