drm/intel_dsi_vbt: Remove duplicate header

Remove video/mipi_display.h which is included more than once

Signed-off-by: Brajeswar Ghosh <brajeswar.linux@gmail.com>
Signed-off-by: Jani Nikula <jani.nikula@intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20181225133055.GA2628@hp-pavilion-15-notebook-pc-brajeswar