drm/panel: simple: Add support for the Frida FRD350H54004 panel

The FRD350H54004 is a simple 3.5" 320x240 24-bit TFT panel, found for
instance inside the Anbernic RG-350 handheld gaming console.

v2: Order alphabetically
v3: Add connector_type, and update timings according to the constraints
    listed in the datasheet

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Link: https://patchwork.freedesktop.org/patch/msgid/20200113161741.32061-3-paul@crapouillou.net