The backlight does not work correctly with the current display panel
configuration: It works after boot, but once the display gets disabled it
is not possible to get it back on. It turns out that the ATNA45AF01 panel
needs exactly the same non-standard power sequence as implemented by the
panel-samsung-atna33xc20 driver for sc7180-trogdor-homestar.

Switch the panel in the DT to the new compatible and make two more changes
to make it work correctly:

 1. Add the missing GPIO for the panel EL_ON3 line (EDP_BL_EN on CRD and
    enable-gpios in the DT).
 2. Drop the regulator-always-on for the panel regulator. The panel does
    not seem to power off properly if the regulator stays on.

Fixes: d7e03cce ("arm64: dts: qcom: x1e80100-crd: Enable more support")
Reviewed-by: Konrad Dybcio <konrad.dybcio@linaro.org>
Signed-off-by: Stephan Gerhold <stephan.gerhold@linaro.org>
Reviewed-by: Johan Hovold <johan+linaro@kernel.org>
Tested-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20240715-x1e80100-crd-backlight-v2-3-31b7f2f658a3@linaro.orgSigned-off-by: Bjorn Andersson <andersson@kernel.org>