mojo/shared: Allow passing in extra options to the gen mojo command

MultiPart: 5/5
Change-Id: I154357a5a82bdafecd6878cce84e1ec8d49083d5
diff --git a/mojo.mk b/mojo.mk
index ee5791d..fbc22f9 100644
--- a/mojo.mk
+++ b/mojo.mk
@@ -75,7 +75,7 @@
 # $4 is language (go, dart, ...).
 define MOJOM_GEN
 	mkdir -p $3
-	$(MOJO_SDK)/src/mojo/public/tools/bindings/mojom_bindings_generator.py $1 -I $2 -d $2 -o $3 -g $4
+	$(MOJO_SDK)/src/mojo/public/tools/bindings/mojom_bindings_generator.py $1 -I $2 -d $2 -o $3 -g $4 $5
 endef
 
 define MOJO_RUN