clk_prepare_enable() may fail, so let's check its return value and propagate it
in the case of error.
Acked-by: NPeter Chen <peter.chen@freescale.com>
Signed-off-by: NFabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: NFelipe Balbi <balbi@ti.com>