systemd: add "system" sub directory

.gitignore

@@ -35,7 +35,7 @@ tags
 /mkinstalldirs
 /build
 /src/mpd
-/systemd/mpd.service
+/systemd/system/mpd.service
 /stamp-h1
 
 /src/dsd2pcm/dsd2pcm

Makefile.am

@@ -1449,8 +1449,8 @@ FILTER_LIBS = \
 
 if HAVE_SYSTEMD
 systemdsystemunit_DATA = \
-	systemd/mpd.socket \
-	systemd/mpd.service
+	systemd/system/mpd.socket \
+	systemd/system/mpd.service
 endif
 
 

configure.ac

@@ -1905,7 +1905,7 @@ dnl Generate files
 dnl ---------------------------------------------------------------------------
 AC_CONFIG_FILES(Makefile)
 AC_CONFIG_FILES(doc/doxygen.conf)
-AC_CONFIG_FILES(systemd/mpd.service)
+AC_CONFIG_FILES(systemd/system/mpd.service)
 AC_OUTPUT
 
 echo 'MPD is ready for compilation, type "make" to begin.'