Alsa upstream added a couple of configure options to disable some plugins but
forgot to reflect these changes in Makefile.am.

--- alsa-plugins-1.1.5/Makefile.am
+++ alsa-plugins-1.1.5/Makefile.am
@@ -1,4 +1,4 @@
-SUBDIRS = oss mix usb_stream arcam-av doc
+SUBDIRS = doc
 if HAVE_JACK
 SUBDIRS += jack
 endif
@@ -20,6 +20,18 @@
 if HAVE_SPEEXDSP
 SUBDIRS += speex
 endif
+if HAVE_OSS
+SUBDIRS += oss
+endif
+if HAVE_MIX
+SUBDIRS += mix
+endif
+if HAVE_USBSTREAM
+SUBDIRS += usb_stream
+endif
+if HAVE_ARCAMAV
+SUBDIRS += arcam-av
+endif
 
 EXTRA_DIST = gitcompile version COPYING.GPL m4/attributes.m4
 AUTOMAKE_OPTIONS = foreign