[ci:skip-build]: build in CI is currently failing with 'BAD signature'
errors; probably caused by outdated Alpine packages in the dl-cdn
mirror, related to the musl-1.2 rebuild in Alpine edge.
At the moment we have Contributor: lines on some packages (but not all of them),
but often they don't represent the actual contributors to the package very well.
E.g. when we added them retroactively to the device packages we only added
the initial contributor (which isn't necessarily the person
who made most of the work for a device...)
The Git history is the most representative source for figuring out
who contributed to a package, so there is no reason to duplicate that
into the APKBUILD.
[skip ci]: way too many packages
* make modules_initfs same as lg-hammerhead
(fixes postmarketOS splash logos at boot)
* split out downstream-firmware and mainline-firmware
* add firmware-adreno to firmware-mainline subpkg
* prepare deviceinfo file to mainline kernel
Prepare for better device categorization by moving everything to testing
subdir first.
[skip-ci]: chicken-egg problem: passing pmaports CI depends on pmbootstrap MR
depends on this MR
Related: postmarketos#16
