MLK-17022 drm/panel: panel-simple: Correct JDI TX26D202VM0BWA panel display timing flags

The JDI TX26D202VM0BWA panel works in data enable(DE) mode.
Apparently, the panel's data enable signal is active high
according to the panel spec.  This patch corrects the DE
signal polarity from active low to active high.

Signed-off-by: Liu Ying <victor.liu@nxp.com>
(cherry picked from commit ed0230ec)