The current panel brightness is only 360 nit. Adjust the power and gamma to
optimize the panel brightness. The brightness after adjustment is 390 nit.

Fixes: 31793387 ("drm/panel: himax-hx83102: Support for IVO t109nw41 MIPI-DSI panel")
Signed-off-by: Cong Yang <yangcong5@huaqin.corp-partner.google.com>
Reviewed-by: Douglas Anderson <dianders@chromium.org>
Reviewed-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Douglas Anderson <dianders@chromium.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20241011020819.1254157-1-yangcong5@huaqin.corp-partner.google.com