package/wpewebkit: add optional systemd dependency

WPE WebKit 2.30.0 added an USE_SYSTEMD buil option, which needs to
be set to avoid CMake from trying to use systemd unconditionally.

Based on a similar patch for package/webkitgtk by Peter Seiderer.

Signed-off-by: Adrian Perez de Castro <aperez@igalia.com>
Reviewed-by: Peter Seiderer <ps.report@gmx.net>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/wpewebkit/wpewebkit.mk

@@ -63,6 +63,13 @@ else
 WPEWEBKIT_CONF_OPTS += -DUSE_WOFF2=OFF
 endif
 
+ifeq ($(BR2_INIT_SYSTEMD),y)
+WPEWEBKIT_CONF_OPTS += -DUSE_SYSTEMD=ON
+WPEWEBKIT_DEPENDENCIES += systemd
+else
+WPEWEBKIT_CONF_OPTS += -DUSE_SYSTEMD=OFF
+endif
+
 # JIT is not supported for MIPS r6, but the WebKit build system does not
 # have a check for these processors. The same goes for ARMv5 and ARMv6.
 # Disable JIT forcibly here and use the CLoop interpreter instead.