drm/panel: simple: Add support for DataImage SCF0700C48GGU18

This adds support for the DataImage SCF0700C48GGU18 7.0" WVGA (800x480)
TFT LCD panel. The panel has 24-bit parallel interface and can be
supported by the simple panel driver.

Signed-off-by: Michal Vokáč <michal.vokac@ysoft.com>
Reviewed-by: Rob Herring <robh@kernel.org>
Signed-off-by: Thierry Reding <treding@nvidia.com>
Link: https://patchwork.freedesktop.org/patch/msgid/1529930490-11874-2-git-send-email-michal.vokac@ysoft.com