firmware: raspberrypi: Add RPI_FIRMWARE_NOTIFY_DISPLAY_DONE

The RPI_FIRMWARE_NOTIFY_DISPLAY_DONE firmware call allows to tell the
firmware the kernel is in charge of the display now and the firmware can
free whatever resources it was using.

Acked-by: Nicolas Saenz Julienne <nsaenz@kernel.org>
Signed-off-by: Maxime Ripard <maxime@cerno.tech>
Link: https://patchwork.freedesktop.org/patch/msgid/20211215095117.176435-2-maxime@cerno.tech

include/soc/bcm2835/raspberrypi-firmware.h

@@ -91,6 +91,7 @@ enum rpi_firmware_property_tag {
 	RPI_FIRMWARE_GET_POE_HAT_VAL =                        0x00030049,
 	RPI_FIRMWARE_SET_POE_HAT_VAL =                        0x00030050,
 	RPI_FIRMWARE_NOTIFY_XHCI_RESET =                      0x00030058,
+	RPI_FIRMWARE_NOTIFY_DISPLAY_DONE =                    0x00030066,
 
 	/* Dispmanx TAGS */
 	RPI_FIRMWARE_FRAMEBUFFER_ALLOCATE =                   0x00040001,