dt-bindings: drm: msm: shd: add dynamic mode support

Add dynamic base mode support and move below properties to optional:

qcom,shared-display-src-mode
qcom,shared-display-dst-mode
qcom,shared-display-base-mst
qcom,shared-display-base-mode

Also added qcom,shared-display-base-connector as an alternative
property of qcom,shared-display-base-intf to align with other modules
like msm-lease.

Change-Id: Ia1ddd69d0afa3cd8c9af29df5f244563dfe326ac
Signed-off-by: Xiaowen Wu <wxiaowen@codeaurora.org>