media: dt-bindings: nxp,imx8-jpeg: Add clocks entries

The JPEG decoder/encoder present in iMX8QXP and iMX8QM SoCs need
the PER and IPG clocks to be functional, so add the clock entries.

This also fixes the following schema warning:

imx8qm-apalis-eval.dtb: jpegdec@58400000: 'assigned-clock-rates', 'assigned-clocks', 'clock-names', 'clocks' do not match any of the regexes: 'pinctrl-[0-9]+'
        from schema $id: http://devicetree.org/schemas/media/nxp,imx8-jpeg.yaml#

Signed-off-by: Fabio Estevam <festevam@denx.de>
Signed-off-by: Mirela Rabulea <mirela.rabulea@nxp.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Hans Verkuil <hverkuil-cisco@xs4all.nl>