This switches the config over to one based on Alpine's linux-gru which
is for an rk3399 chromebook. It produces way smaller kernels and has
more general purpose hardware support.
Enable SATA host support, the AHCI driver, and SCSI disk support so that
some generic PCIe SATA cards will properly detect and mount SATA drives
connected to them.
Tested on a RockPro64 with 2 3.5" drives connected in RAID 0 to an
Ableconn PEXSA115A 2-port PCIe x2 card (ASM1062).
* Add u-boot build with a lot of patches that makes the display work in
u-boot for boot selection
* Upgrade the rockchip kernel to 5.11 mainline with config for the
rk3399 devices built-in
* Make the rockpro64 and pinebook pro use the newer kernel
[ci:skip-build]
