Adding code for Opus Custom
diff --git a/opus_sources.mk b/opus_sources.mk
index 077d211..06df75a 100644
--- a/opus_sources.mk
+++ b/opus_sources.mk
@@ -1,2 +1,3 @@
-OPUS_SOURCES = src/opus_decoder.c \
+OPUS_SOURCES = src/opus.c \
+src/opus_decoder.c \
 src/opus_encoder.c