dt-bindings: clock: Add support for 5nm C-PHY shadow clock

Add support for 5nm DSI PLL C-PHY shadow clocks, which
will be used during dynamic dsi clock switch.

Change-Id: I6aed40f7347b5a098c6c7f4d160d5456424a3507
Signed-off-by: Satya Rama Aditya Pinapala <psraditya30@codeaurora.org>