Remove the TVM submodule (#273)

Delete TVM submodule

Author: binarybana

.gitmodules

@@ -7,6 +7,3 @@
 [submodule "3rdparty/googletest"]
 	path = 3rdparty/googletest
 	url = https://github.com/google/googletest.git
-[submodule "3rdparty/tvm"]
-	path = 3rdparty/tvm
-	url = https://github.com/mlc-ai/relax.git