dt-bindings: display: msm/dsi: Add updates for SDM845

SDM845 uses a newer revision (v2.0+) of the 6G DSI controller. This
revision has another clock input at the block boundary called the byte
interface clock. Specify this new clock in the binding.

A 10nm DSI PHY is used along with the controller. Add a compatible
string for it and specify its base address/regulator supply needs.

Cc: Rob Herring <robh@kernel.org>
Cc: devicetree@vger.kernel.org
Signed-off-by: Archit Taneja <architt@codeaurora.org>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>