crypto: ensure qapi/crypto.json is listed in qapi-modules

The rebuild of qapi-types.c/h is not correctly triggered
when qapi/crypto.json is changed because it was missing
from the list of files in the qapi-modules variable.

Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
diff --git a/Makefile b/Makefile
index af3e5f1..82b2fc8 100644
--- a/Makefile
+++ b/Makefile
@@ -271,7 +271,8 @@
 
 qapi-modules = $(SRC_PATH)/qapi-schema.json $(SRC_PATH)/qapi/common.json \
                $(SRC_PATH)/qapi/block.json $(SRC_PATH)/qapi/block-core.json \
-               $(SRC_PATH)/qapi/event.json $(SRC_PATH)/qapi/introspect.json
+               $(SRC_PATH)/qapi/event.json $(SRC_PATH)/qapi/introspect.json \
+               $(SRC_PATH)/qapi/crypto.json
 
 qapi-types.c qapi-types.h :\
 $(qapi-modules) $(SRC_PATH)/scripts/qapi-types.py $(qapi-py)