Document a compatible string for the rk3506 dsi-dphy. Signed-off-by: Chaoyi Chen <chaoyi.chen@rock-chips.com> Acked-by: Conor Dooley <conor.dooley@microchip.com> Link: https://patch.msgid.link/20251106020632.92-3-kernel@airkyi.com Signed-off-by: Vinod Koul <vkoul@kernel.org>