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

This reverts 'commit 4843e194 ("drm/msm/dsi-staging:
add hardware driver for dsi phy")'
This is partial change for display drm driver,
that will break drm/sde merge commit.

Change-Id: Ifb18bac24f47a359394fc4d253803a2dd4720de3
Signed-off-by: Narendra Muppalla <NarendraM@codeaurora.org>