Add support for plugins (and specifically GPRS encryption plugins)
diff --git a/include/osmocom/crypt/Makefile.am b/include/osmocom/crypt/Makefile.am
new file mode 100644
index 0000000..7ce69fd
--- /dev/null
+++ b/include/osmocom/crypt/Makefile.am
@@ -0,0 +1,3 @@
+osmocrypt_HEADERS = gprs_cipher.h
+
+osmocryptdir = $(includedir)/osmocom/crypt