dt-bindings: clock: add support for 10nm DSI PLL shadow clock

Add clock id for 10nm DSI PLL shadow clocks, which will be
used during dynamic dsi clock switch.

CRs-Fixed: 2314658
Change-Id: Ifcbeeab2f85f36cb0e872bf1a9ffcdeb479fb9fa
Signed-off-by: Sandeep Panda <spanda@codeaurora.org>
Signed-off-by: Yujun Zhang <yujunzhang@codeaurora.org>