dt-bindings: display: Add Sitronix ST7571 LCD Controller

dt-bindings: display: Add Sitronix ST7571 LCD Controller

Sitronix ST7571 is a dot matrix LCD controller supporting
both 4bit grayscale and monochrome LCDs.

Reviewed-by: Conor Dooley <conor.dooley@microchip.com>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
Reviewed-by: Krzysztof Kozlowski <krzysztof.kozlowski@linaro.org>
Signed-off-by: Marcus Folkesson <marcus.folkesson@gmail.com>
Link: https://lore.kernel.org/r/20250423-st7571-v6-1-e9519e3c4ec4@gmail.com
Signed-off-by: Javier Martinez Canillas <javierm@redhat.com>