systemd/systemd: build with SELinux support

Now that Alpine's linux-pam comes with pam_selinux.so, we will no longer
break setups that don't include SELinux.

Part-of: <https://gitlab.postmarketos.org/postmarketOS/pmaports/-/merge_requests/9482>

extra-repos/systemd/systemd-stage0/APKBUILD

@@ -5,7 +5,7 @@ pkgname=systemd-stage0
 pkgver=262_rc1
 _pkgver="${pkgver/_/-}"
 # pkgrel must match systemd!
-pkgrel=0
+pkgrel=1
 pkgdesc="Minimal systemd bootstrap package"
 url="https://github.com/systemd/systemd"
 # armhf: pmb#2618

extra-repos/systemd/systemd/APKBUILD

@@ -17,7 +17,7 @@ pkgname=systemd
 pkgver=262_rc1
 _pkgver="${pkgver/_/-}"
 # pkgrel must match systemd-stage0!
-pkgrel=0
+pkgrel=1
 pkgdesc="System and service manager"
 url="https://github.com/systemd/systemd"
 # armhf: no linux-stable
@@ -145,6 +145,7 @@ depends="
 	libpwquality
 	libqrencode
 	libseccomp
+	libselinux
 	libxkbcommon
 	linux-pam
 	lz4-libs
@@ -289,7 +290,7 @@ build() {
 		-Dbootloader="$_bootloader" \
 		-Dinitrd=true \
 		-Dhibernate=false \
-		-Dselinux=disabled \
+		-Dselinux=enabled \
 		-Dukify=disabled \
 		-Dtpm2=enabled \
 		\