update submodule to edk2-stable201908

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

diff --git a/edk2 b/edk2
index 20d2e5a125e34fc8501026613a71549b2a1a3e54..37eef91017ad042035090cae46557f9d6e2d5917 160000 (submodule)
--- a/edk2
+++ b/edk2
@@ -1 +1 @@
-Subproject commit 20d2e5a125e34fc8501026613a71549b2a1a3e54
+Subproject commit 37eef91017ad042035090cae46557f9d6e2d5917