package/rpi-firmware: bump for misc fixes/improvements

Bring a slew of fixes and improvements to:
  - boot hang
  - camera zoom, night mode
  - MJPEG decoder/encoder
  - video decoder/encoder
  - dispmanx (3D engine)
  - documentation

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/rpi-firmware/rpi-firmware.mk

@@ -4,7 +4,7 @@
 #
 ################################################################################
 
-RPI_FIRMWARE_VERSION = e618d4ff2dc20051bc726834b22487fe2e236fe5
+RPI_FIRMWARE_VERSION = 940dc3b5ea0a001096c5fbb2d483a961d42fe85c
 RPI_FIRMWARE_SITE = $(call github,raspberrypi,firmware,$(RPI_FIRMWARE_VERSION))
 RPI_FIRMWARE_LICENSE = BSD-3c
 RPI_FIRMWARE_LICENSE_FILES = boot/LICENCE.broadcom