drm/msm/dsi-staging: dsi resource handling for continuous splash

For continuous splash use case bootloader already takes
care of dsi hardware states including clocks and regulators.
This change avoids touching dsi hardware blocks during
DSI initialization sequence.

Change-Id: I8b0aa6b2d6f4f4bc45d1c51b1f3c18fe940d11ea
Signed-off-by: Shashank Babu Chinta Venkata <sbchin@codeaurora.org>
Signed-off-by: Chandan Uddaraju <chandanu@codeaurora.org>