ARM: dts: imx6q-logicpd: Fix broken PWM

The DTC doesn't like the default PWM settings, because it's expecting
three cells.  This patch reduces adds the extra entry of 0 to the PWM
reference.

Fixes:  fa28d821

 ("ARM: dts: imx: default to #pwm-cells = <3> in the SoC dtsi files")
Reviewed-by: Fabio Estevam <festevam@gmail.com>
Signed-off-by: Adam Ford <aford173@gmail.com>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>