remove ffasn1c generated hnbap.[ch] from source

we want to use asn1c instead.
diff --git a/src/hnbap.c b/src/hnbap.c
deleted file mode 120000
index 9373ccc..0000000
--- a/src/hnbap.c
+++ /dev/null
@@ -1 +0,0 @@
-../asn1/hnbap/ffasn1c/hnbap.c
\ No newline at end of file
diff --git a/src/hnbap.h b/src/hnbap.h
deleted file mode 120000
index 6b16029..0000000
--- a/src/hnbap.h
+++ /dev/null
@@ -1 +0,0 @@
-../asn1/hnbap/ffasn1c/hnbap.h
\ No newline at end of file