mdss: display: always send both column and page to panel

At partial update, When broadcast mode enabled, dsi1 is used
to trigger dcs command to be sent to both panel. Therefore
set_col_page dcs command of dsi1 can not be skipped even its
roi has not changed.

CRs-Fixed: 679218
Change-Id: Id979433fc3993dfb5e6aee4b9779c2cde42617f1
Signed-off-by: Kuogee Hsieh <khsieh@codeaurora.org>