ci: Include db410c support in the ARM container.

ci: Include db410c support in the ARM container.

I'm working on moving the db410c CI from docker to LAVA, which means we
get to boot a custom kernel.  To do that, we need to enable ARCH_QCOM in
the kernel, save the dtb around, and include abootimg in our container so
that we can generate combined kernel/dtb/ramdisk images for fastboot.

LAVA's fastboot support is unable to pack the overlay into an abootimg
image, just a cpio rootfs.  We could flash the cpio rootfs after overlay
addition, but that takes 2 minutes to do, and causes wear on the devices.
Instead, we'll bring up the network at boot and use wget to fetch the
overlay.  We'll want network support anyway, so that we can transfer the
failure xmls back to the gitlab job's artifacts at some point.

Since the msm GPU and realtek network firmware increase our payload by
3MB, add in firmware compression so that it doesn't waste as much RAM on
devices not using it.

Reviewed-by: Tomeu Vizoso <tomeu.vizoso@collabora.com>
Tested-by: Marge Bot <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3928>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/3928>