ARM: dts: imx: add required #clock-cells for fixed-clock

Per bindings of fixed-clock, #clock-cells is a required property.  Let's
add it for those fixed rate clocks.

Signed-off-by: Shawn Guo <shawn.guo@freescale.com>

diff --cc arch/arm/boot/dts/imx25.dtsi
Simple merge

diff --cc arch/arm/boot/dts/imx27-apf27.dts
Simple merge

diff --cc arch/arm/boot/dts/imx27.dtsi
Simple merge

diff --cc arch/arm/boot/dts/imx50.dtsi
Simple merge

diff --cc arch/arm/boot/dts/imx51.dtsi
Simple merge

diff --cc arch/arm/boot/dts/imx53.dtsi
Simple merge

diff --cc arch/arm/boot/dts/imx6qdl.dtsi
Simple merge

diff --cc arch/arm/boot/dts/imx6sl.dtsi
Simple merge

diff --cc arch/arm/boot/dts/vf610-twr.dts
Simple merge

diff --cc arch/arm/boot/dts/vf610.dtsi
Simple merge