ARM: dts: imx: add required clocks and clock-names for ccm

ARM: dts: imx: add required clocks and clock-names for ccm

Add required clocks and clock-names for ccm to fix below CHECK_DTBS
warnings:
  arch/arm/boot/dts/nxp/imx/imx6dl-alti6p.dtb: clock-controller@20c4000 (fsl,imx6q-ccm): clock-names:0: 'osc' was expected
        from schema $id: http://devicetree.org/schemas/clock/imx6q-clock.yaml#

Reviewed-by: Daniel Baluta <daniel.baluta@nxp.com>
Reviewed-by: Peng Fan <peng.fan@nxp.com>
Signed-off-by: Frank Li <Frank.Li@nxp.com>