arm64: dts: visconti: Add clock controller support for TMPV7708

Adds node of clock controller support for Toshiba Visconti TMPV7708.

Signed-off-by: Nobuhiro Iwamatsu <nobuhiro1.iwamatsu@toshiba.co.jp>
Link: https://lore.kernel.org/r/20220421080143.2135566-1-nobuhiro1.iwamatsu@toshiba.co.jp/