Comment 0 for bug 1691407

To properly support the Compute Module 3 we need an dtb update, and while here i imported all the fixes that were sitting in the raspberry-4.4 upstream tree: there are 35 patches in total, roughly splitted like this:

~20 patches are code fixes: 5 for clocks, 5 for drm/vc4, 1 usb, 1 for vpf (does not apply to us), 1 for gpio, 4 for snd, 1 rng driver and 1 for the lirc driver
~10 dts patches:
 -1 new dts to support the new raspberry zero w board
 -and a bunch of fixes for various dtb overlays (pi sound, disable-wifi, mcp adc,
-the remaning patches are config changes for their bcm defconfig

The resulting kernel was tested on rpi2/rpi3 with ubuntu classic and ubuntu core, and on the compute module 3.

1: https://www.raspberrypi.org/blog/compute-module-3-launch/