Update 4.9.80, use defconfig files, support Pi3 B+

[StefanScherer]

• Use defconfig files to make it easier to diff our changes to upstream

  • arch/arm/configs/bcmrpi_defconfig
  • arch/arm/configs/bcm2709_defconfig

• Update to Kernel 4.9.80

• Support Raspberry Pi 3 B+

[StefanScherer]

The diff of our defconfigs is just

stefan@rpi-kernel:~$ diff rpi-kernel/kernel_configs/rpi1_docker_defconfig /var/kernel_build/cache/linux-kernel/arch/arm/configs/bcmrpi_defconfig 
16d15
< CONFIG_MEMCG_SWAP=y
18,20d16
< CONFIG_CFS_BANDWIDTH=y
< CONFIG_RT_GROUP_SCHED=y
< CONFIG_CGROUP_PIDS=y
25d20
< CONFIG_CGROUP_PERF=y
354,355d348
< CONFIG_NET_L3_MASTER_DEV=y
< CONFIG_CGROUP_NET_PRIO=y
461d453
< CONFIG_IPVLAN=m

[StefanScherer]

Test with https://github.com/StefanScherer/image-builder-raspbian/releases/tag/v18.02.0-ce SD card image (which is Raspbian 20180313 + Docker) on a RPi 3 B+:

wget https://62-32913687-gh.circle-artifacts.com/0/home/circleci/project/output/20180320-092128/raspberrypi-kernel_20180320-092128_armhf.deb
sudo rm /boot/bcm2710-rpi-3-b-plus.dtb
sudo dpkg -i raspberrypi-kernel_20180320-092128_armhf.deb 
sudo reboot

Checking the Kernel

wget https://raw.githubusercontent.com/moby/moby/master/contrib/check-config.sh
chmod +x check-config.sh 
sudo modprobe configs
./check-config.sh 

Looks good!

[StefanScherer]

First test with a new image-builder-rpi build looks also very good. Ready to merge