[mpact][torch-mlir] bump to torch-mlir@6fece25ff3203bbc538 (#55)

diff --git a/externals/torch-mlir b/externals/torch-mlir
index c7d52f6..6fece25 160000
--- a/externals/torch-mlir
+++ b/externals/torch-mlir
@@ -1 +1 @@
-Subproject commit c7d52f63b482b2c30f4efb435ce0cc2efeab25d9
+Subproject commit 6fece25ff3203bbc538756beb83fd513c19bcd7d