qapi: create two block related json modules

qapi/block-core.json contains block definitions unrelated to emulation.

qapi/block.json is a superset of the previous and contains definitions related
to emulation.

The purpose of these extractions is to be able to hook qapi/block-core.json
generated code on qemu-nbd.
Signed-off-by: NBenoit Canet <benoit@irqsave.net>
Reviewed-by: NEric Blake <eblake@redhat.com>
Signed-off-by: NStefan Hajnoczi <stefanha@redhat.com>

qapi-schema.json

@@ -5,6 +5,9 @@
 # QAPI common definitions
 { 'include': 'qapi/common.json' }
 
+# QAPI block definitions
+{ 'include': 'qapi/block.json' }
+
 ##
 # LostTickPolicy:
 #

qapi/block-core.json

+# -*- Mode: Python -*-
+#
+# QAPI block core definitions (vm unrelated)
+
+# QAPI common definitions
+{ 'include': 'common.json' }

qapi/block.json

+# -*- Mode: Python -*-
+#
+# QAPI block definitions (vm related)
+
+# QAPI block core definitions
+{ 'include': 'block-core.json' }
+