!4180 remove unused submodule incubator-tvm

Merge pull request !4180 from looop5/remove_submodule

.gitmodules

@@ -5,9 +5,6 @@
 [submodule "third_party/googletest"]
 	path = third_party/googletest
 	url = https://github.com/google/googletest.git
-[submodule "third_party/incubator-tvm"]
-	path = third_party/incubator-tvm
-	url = https://github.com/apache/incubator-tvm.git
 [submodule "third_party/protobuf"]
 	path = third_party/protobuf
 	url = https://github.com/protocolbuffers/protobuf.git

third_party/incubator-tvm

@@ -1 +0,0 @@
-Subproject commit c6f8c23c349f3ef8bacceaf3203f7cc08e6529de