device-kobo-clara: cleanup boot process to use extlinux

To avoid custom commands we need to go to near mainline u-boot. That cannot again cannot boot without custom commands boot downstream kernels, so split out downstream business.

Reason for being draft: u-boot does not get updated on the raw sectors, only fresh installs work

device/testing/device-kobo-clara/APKBUILD

+# Maintainer: Andreas Kemnade <andreas@kemnade.info>
 # Reference: <https://postmarketos.org/devicepkg>
 pkgname=device-kobo-clara
 pkgdesc="Kobo Clara HD"
-pkgver=0.7
-pkgrel=5
+pkgver=1
+pkgrel=0
 url="https://postmarketos.org"
 license="MIT"
 arch="armv7"
 options="!check !archcheck"
 depends="
+	linux-kobo-clara-mainline
 	kobo-epdc-extractor
 	perl
 	postmarketos-base
 	u-boot-kobo-clara
-	u-boot-tools
 "
 makedepends="devicepkg-dev"
-subpackages="
-	$pkgname-kernel-downstream:kernel_downstream
-	$pkgname-kernel-mainline:kernel_mainline
-	$pkgname-nonfree-firmware:nonfree_firmware
-"
 source="
 	deviceinfo
-	modules-initfs.mainline
-	uboot-script-downstream.cmd
-	uboot-script-mainline.cmd
+	modules-initfs
 "
 
 build() {
@@ -35,35 +29,7 @@ package() {
 	devicepkg_package $startdir $pkgname
 }
 
-kernel_downstream() {
-	pkgdesc="Downstream kernel"
-	depends="linux-kobo-clara"
-	devicepkg_subpackage_kernel $startdir $pkgname $subpkgname
-
-	mkimage -A arm -O linux -T script -n postmarketOS \
-		-d "$srcdir"/uboot-script-downstream.cmd "$srcdir/boot-downstream.scr"
-	install -Dm644 "$srcdir/boot-downstream.scr" "$subpkgdir/boot/boot.scr"
-}
-
-kernel_mainline() {
-	pkgdesc="Close to mainline kernel"
-	depends="linux-kobo-clara-mainline"
-	devicepkg_subpackage_kernel $startdir $pkgname $subpkgname
-
-	mkimage -A arm -O linux -T script -n postmarketOS \
-		-d "$srcdir/uboot-script-mainline.cmd" "$srcdir/boot-mainline.scr"
-	install -Dm644 "$srcdir/boot-mainline.scr" "$subpkgdir/boot/boot.scr"
-}
-
-nonfree_firmware() {
-	pkgdesc="Kobo Clara HD firmware"
-	depends="firmware-kobo-clara"
-	mkdir "$subpkgdir"
-}
-
 sha512sums="
-bdc2528bd09f164870a368caf0b06a6c816b883536c3033384060bcf480ddf987daf38db4b523406e1e591f9cea86c9bb97276d88ebc3b05e2ae6bb53adb4ba8  deviceinfo
-5d53ee902538e53c4fe79eaef8e3800b9d3f73ec70d2a9887ddb11a6715ca76ce17128e3c02c2b6f2f575fb86f15c2415c24466d4b1a031f7a346d0db186dcb1  modules-initfs.mainline
-4bfc2714a2670efc451860bd97d36ba12559e00aed41afdde1ac3e01b41458390358ac7f6bc96a6dee6be6a34f534da52d845b02df0566b25f4868774ef69b1d  uboot-script-downstream.cmd
-9f624e90df6bc6acbd6db03d4319a778443b270e5756a2bc78002df8da19d23a3ea652f3d8da15257552a7381646b83553f794d24f6ef31479d3a16af9ae5e0b  uboot-script-mainline.cmd
+b93b62ac7af499e9170dc78329ae6092fb79a3657a62ea1ee5b383a6ccc596e36382c1156f8d168aa1de89dc7bf3e5b9f266a49f56c51233aac8cc598facde68  deviceinfo
+5d53ee902538e53c4fe79eaef8e3800b9d3f73ec70d2a9887ddb11a6715ca76ce17128e3c02c2b6f2f575fb86f15c2415c24466d4b1a031f7a346d0db186dcb1  modules-initfs
 "