linux-postmarketos-exynos5: add package

This adds a kernel package for exynos5 devices. Config has been based on linux-postmarketos-exynos4's config and Hardkernel's odroid xu4 config.

New device odroid-xu4 is added which uses it. It is similar to odroid-hc2, and could use the same firmware package, but I opted for the slightly newer blobs from the 2020.01 branch in Hardkernel's repo.

Initial dtbs for Samsung-chagallwifi and samsung-klimtlte are also added, and a mainline kernel option added for the devices. The initial dtbs support:

• Installing PostmarketOS to internal, or external, storage
• Usb networking
• Getting logs over UART

samsung-chagallwifi patches have been sent to samsung-soc mailing list.

device/testing/device-samsung-chagallwifi/APKBUILD

@@ -3,16 +3,20 @@
 # Reference: <https://postmarketos.org/devicepkg>
 pkgname=device-samsung-chagallwifi
 pkgdesc="Samsung Galaxy Tab S 10.5"
-pkgver=0.1
-pkgrel=3
+pkgver=1
+pkgrel=0
 url="https://postmarketos.org"
 license="MIT"
 arch="armv7"
 options="!check !archcheck"
-depends="postmarketos-base linux-samsung-chagallwifi mkbootimg mesa-dri-swrast msm-fb-refresher"
+depends="postmarketos-base mkbootimg"
 makedepends="devicepkg-dev"
 source="deviceinfo"
-subpackages="$pkgname-nonfree-firmware:nonfree_firmware"
+subpackages="
+	$pkgname-kernel-downstream:kernel_downstream
+	$pkgname-kernel-mainline:kernel_mainline
+	$pkgname-nonfree-firmware:nonfree_firmware
+"
 
 build() {
 	devicepkg_build $startdir $pkgname
@@ -22,6 +26,18 @@ package() {
 	devicepkg_package $startdir $pkgname
 }
 
+kernel_downstream() {
+	pkgdesc="Display and wifi works (see device table for details)"
+	depends="linux-samsung-chagallwifi mesa-dri-swrast msm-fb-refresher"
+	devicepkg_subpackage_kernel $startdir $pkgname $subpkgname
+}
+
+kernel_mainline() {
+	pkgdesc="Mainline WIP (usb networking works but not much else)"
+	depends="linux-postmarketos-exynos5"
+	devicepkg_subpackage_kernel $startdir $pkgname $subpkgname
+}
+
 nonfree_firmware() {
 	pkgdesc="Non-free firmware for the Samsung Galaxy Tab S"
 	depends="firmware-samsung-chagall"
@@ -29,5 +45,5 @@ nonfree_firmware() {
 }
 
 sha512sums="
-b6dbcae026861dc9c31c804d0388ec24ceac313692b901b6d159134710892b89e798878cae8e41a26167b3c3b5e7f6360818cec84fdbd22fbcd77bf4a48dcc8b  deviceinfo
+3928540b95d988b0264da86c43bedd0c3e66f9b0d60a795fe26c976da383aee0d1a3819d1aa819af9637f7540c2cefdd2e1decf7b4dc060e6327d303d8e5cebc  deviceinfo
 "