update qemu submodule to v4.0.0

Signed-off-by: Thomas Lamprecht <t.lamprecht@proxmox.com>

diff --git a/qemu b/qemu
index 1dfcf652e6ae5eb6b98d2c55a509e8eb054a2fab..131b9a05705636086699df15d4a6d328bb2585e8 160000 (submodule)
--- a/qemu
+++ b/qemu
@@ -1 +1 @@
-Subproject commit 1dfcf652e6ae5eb6b98d2c55a509e8eb054a2fab
+Subproject commit 131b9a05705636086699df15d4a6d328bb2585e8