testing/powkiddy-x55-mapper: split openrc subpackage (MR 5412)

[ci:skip-build]: already built successfully in CI

device/testing/powkiddy-x55-mapper/APKBUILD

 pkgname=powkiddy-x55-mapper
 pkgver=1.0.1
-pkgrel=0
+pkgrel=1
 pkgdesc="Powkiddy X55 gamepad joiner/mapper"
 url="https://github.com/vognev/x55-mapper"
 arch="aarch64"
@@ -8,19 +8,25 @@ license="MIT"
 options="!check"
 makedepends="cargo"
 source="powkiddy-x55-mapper-$pkgver.tar.gz::https://github.com/vognev/x55-mapper/archive/refs/tags/v$pkgver.tar.gz"
-install="$pkgname.post-install $pkgname.pre-deinstall"
 builddir="$srcdir/x55-mapper-$pkgver"
+subpackages="$pkgname-openrc"
 
 build() {
 	cargo build --release --locked
 }
 
 package() {
-	install -Dm755 contrib/postmarketos/powkiddy-x55-mapper.initd "$pkgdir"/etc/init.d/powkiddy-x55-mapper
 	install -Dm644 contrib/postmarketos/99-disable-real-gamepad.rules -t "$pkgdir"/etc/udev/rules.d/
 	install -Dm755 target/release/x55-mapper -t "$pkgdir"/usr/bin/
 }
 
+openrc() {
+	install="$subpkgname.post-install $subpkgname.pre-deinstall"
+	default_openrc
+
+	install -Dm755 "$builddir"/contrib/postmarketos/powkiddy-x55-mapper.initd "$subpkgdir"/etc/init.d/powkiddy-x55-mapper
+}
+
 sha512sums="
 ebec121a3c7b50c43feffed9082743580a90f0916c4d8e7dd832d8c21ae60b6b23ccd9c36c3b24ec13d17a8f0f50ece53d6b86b2adef8a82d841890394855f9b  powkiddy-x55-mapper-1.0.1.tar.gz
 "