main/postmarketos-base-downstream: add package (MR 4497)

All devices that use downstream kernels should depend on this package.
We will to start with use it to fix so that lightdm+x11 work again
when using downstream kernels.

See also https://gitlab.com/postmarketOS/pmaports/-/issues/2102.

main/postmarketos-base-downstream/10-logind-check-graphical.conf

@@ -0,0 +1,5 @@
+# let LightDM start Xorg even though we don't have graphics driver
+# https://github.com/canonical/lightdm/commit/77a7c6b7b8ca896b98ef43826641bdd520650bfb
+
+[LightDM]
+logind-check-graphical=false

main/postmarketos-base-downstream/APKBUILD

@@ -0,0 +1,25 @@
+# Maintainer: Henrik Grimler <henrik@grimler.se>
+pkgname=postmarketos-base-downstream
+pkgver=1
+pkgrel=0
+pkgdesc="Base package for devices with downstream (vendor) kernels"
+url="https://postmarketos.org"
+arch="noarch"
+license="GPL-3.0-or-later"
+subpackages="$pkgname-lightdm"
+source="10-logind-check-graphical.conf"
+
+package() {
+	mkdir -p "$pkgdir"
+}
+
+lightdm() {
+	install_if="$pkgname=$pkgver-r$pkgrel lightdm"
+
+	install -Dm644 "$srcdir"/10-logind-check-graphical.conf \
+		-t "$subpkgdir"/usr/share/lightdm/lightdm.conf.d
+}
+
+sha512sums="
+00addbea452dd3e2cb90e18793becc47d22118e6b99a79b76eb57db02aa8b00b133569beaea81cce4b39c9e556280c1d6ac8ab687016354e2d189734e38768cf  10-logind-check-graphical.conf
+"