The Jasonic JT240MHQS-HWT-EK-E3 is a custom panel using the Sitronix
ST7789V controller. While the controller features a resolution of
320x240, only an area of 280x240 is visible by design.

Signed-off-by: Michael Riesch <michael.riesch@wolfvision.net>
Reviewed-by: Neil Armstrong <neil.armstrong@linaro.org>
Signed-off-by: Neil Armstrong <neil.armstrong@linaro.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20230718-feature-lcd-panel-v2-4-2485ca07b49d@wolfvision.net