Convert all the 'simple' panels which match the constraints of the
common panel-simple.yaml schema. This conversion is based on how the
panels are documented. Some may turn out to be more complex once the
schema is applied to actual dts files.

Cc: Maxime Ripard <mripard@kernel.org>
Cc: Chen-Yu Tsai <wens@csie.org>
Cc: Thierry Reding <thierry.reding@gmail.com>
Reviewed-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Rob Herring <robh@kernel.org>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200119210907.24152-1-robh@kernel.org