drm/msm: reorder component add to accommodate continuous splash

Add connectors before parsing boot displays. This information
is needed to handle continuous splash. Expose new API to
support continuous splash configuration.

Change-Id: If8ad97298822b7ad2c7e7d706331ee4a7e5af347
Signed-off-by: Chandan Uddaraju <chandanu@codeaurora.org>