Revert "drm/msm/dsi-staging: add hardware driver for dsi controller"

This reverts 'commit a47691f8 ("drm/msm/dsi-staging:
add hardware driver for dsi controller")'
This is partial change for display drm driver,
that will break drm/sde merge commit.

Change-Id: I8d8f93eef70c9028eb5e31b6b9e280b30a26ad13
Signed-off-by: Narendra Muppalla <NarendraM@codeaurora.org>