Google Pixel 3: new device

Add support for the Google Pixel 3 based on Petr Hodina's original device packages, and @Drakulix 's recent work getting support into the sdm845 kernel.

Support status is similar to other SDM845 devices, however audio support is missing and battery status reporting may be inaccurate (since we don't support the additional fuel gauge chip on the device).

This depends on !5486 (merged) being updated and merged.

device/testing/firmware-google-blueline-dtbo/APKBUILD

+# Maintainer: Victoria Brekenfeld <postmarketos@drakulix.de>
+# Co-Maintainer: Joel Selvaraj <joelselvaraj.oss@gmail.com>
+# Co-Maintainer: Caleb Connolly <caleb@postmarketos.org>
+
+pkgname=firmware-google-blueline-dtbo
+pkgver=1
+pkgrel=0
+_commit="88468ea69b2598551861cb48f0785463a61f066c"
+pkgdesc="dtbo.img needed to boot mainline on Pixel 3"
+url="https://gitlab.com/phodina/dtbo-google-blueline"
+arch="aarch64"
+license="GPL-2.0-only"
+makedepends="dtc android-tools"
+source="$pkgname-$_commit.tar.gz::https://gitlab.com/phodina/dtbo-google-blueline/-/archive/$_commit.tar.gz"
+options="!check !archcheck !strip !tracedeps pmb:cross-native"
+builddir="$srcdir/dtbo-google-blueline-$_commit"
+
+build() {
+	dtc -O dtb -o sdm845-b1-dvt1.1.dtbo -b 0 -@ sdm845-b1-dvt.dts
+	mkdtboimg cfg_create dtbo.img dtboimg.cfg
+}
+
+package() {
+	install -D -m644 dtbo.img \
+		"$pkgdir"/boot/dtbo-google-blueline.img
+}
+
+sha512sums="7c8e27ab8c29027b53a699954f62571a6750a3c7337659d166507b063a843feff9e357f0b5f5ebbb30ffbb8ae7f4bc7fe3da267cb86b0c77c2e36d62fb471061  firmware-google-blueline-dtbo-88468ea69b2598551861cb48f0785463a61f066c.tar.gz"