commit ae3e57ae upstream.

Some i.mx platforms need three clocks to let controller work, but
others only need one, refine clock operation to adapt for all
platforms, it fixes a regression found at i.mx27.
Signed-off-by: Peter Chen <peter.chen@freescale.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>