device-htc-m8: enable initfs_extra for downstream kernel (MR 5919)

The full initramfs is now too big for the boot partition.

When building with the downstream kernel, use initfs-extra
to split the initramfs so it can fit again.

This is not an issue with mainline kernel since booting it
uses extlinux with lk2nd.

[ci:skip-vercheck]

Signed-off-by: Alexandre Messier <alex@me.ssier.org>
[ci:skip-build]: already built successfully in CI

device/testing/device-htc-m8/APKBUILD

 # Reference: <https://postmarketos.org/devicepkg>
 pkgname=device-htc-m8
 pkgdesc="HTC One M8"
-pkgver=2
+pkgver=3
 pkgrel=0
 url="https://postmarketos.org"
 license="MIT"
@@ -53,7 +53,7 @@ nonfree_firmware() {
 }
 
 sha512sums="
-697e5942ee2f900e4827495cc4deb4e2eaf76329146c554410d1e9c234d10026bf1a1bb655048d099753dc270d0c4cba2207f592c49bf06a5153dee7fa65c8e4  deviceinfo
+e3432d0710a78e49fdb7b0bfadb4bee8dbe30f733c6c9040560c61a8f9423a48407da723a85cb5e13ea614f0038bd4ac160de4311f5faaa0e4d109b301b00504  deviceinfo
 765abaad5fda0dfda5e62e1e48414d3eea822198f39d0792171a04d73f86f6273a6e562afab430cbfcdd084412568a0ad03d012e9c40c5564f5cd1b9c0f181eb  initfs-hook.sh
 f0f69ab3b5b3fed11ec5049f37c71c4e9dcf87dc1f238199a3917dd61957d46783a8798d63d400cc5d3983987e750e3fec6d7117561ad5005f28131ae4821d66  90-android-touch-dev.rules
 "

device/testing/device-htc-m8/deviceinfo

@@ -14,6 +14,7 @@ deviceinfo_append_dtb_mainline="true"
 deviceinfo_chassis="handset"
 deviceinfo_keyboard="false"
 deviceinfo_external_storage="true"
+deviceinfo_create_initfs_extra_downstream="true"
 
 # Bootloader related
 deviceinfo_flash_method="fastboot"