drm/msm/dsi: fix panel physical dimensions updated to connector

Change overrides the panel physical dimensions with correct
value upto a precision of millimeter, which was getting
truncated to centimeter as drm structures maintain it in
centimeters.

Change-Id: I035357596ed42154b657b791846aee6f940f2e53
Signed-off-by: Vara Reddy <varar@codeaurora.org>