Update libresoc-litex submodule

diff --git a/src/soc/litex/florent b/src/soc/litex/florent
index d1c6391d0c35d1b375e9f12253b2b9f9031e0c3c..42f7357660b245c4491297d24eebc28b4ac2c21f 160000 (submodule)
--- a/src/soc/litex/florent
+++ b/src/soc/litex/florent
@@ -1 +1 @@
-Subproject commit d1c6391d0c35d1b375e9f12253b2b9f9031e0c3c
+Subproject commit 42f7357660b245c4491297d24eebc28b4ac2c21f