During DSC-NonDSC usecase, submode should be passed to
dsi_display_find_mode to differentiate between the modes
containing same timing info. This change adds submode
argument to find the correct mode in such cases.
Change-Id: I82284aeb9c3fd187c4f0961443dd1d0893a3c094
Signed-off-by: Yashwanth <yvulapu@codeaurora.org>