drm/msm/dp: invoke device tree parser on probe

Call device tree parser in probe after initialization of
parser sub-module. Currently it is being called in DRM bind
call that happens after DP driver is registered with DRM.
In case a cable connect event is received before the bind
call, other sub-modules like power may crash as parse has
not been called yet. Call parser as soon as parser sub-module
is ready to avoid uninitialized data access.

CRs-Fixed: 2134333
Change-Id: Id25b70d2e4fd59dbd36e6db2173b54b687914fe5
Signed-off-by: Ajay Singh Parmar <aparmar@codeaurora.org>