update edk2 submodule to edk2-stable202108

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

diff --git a/edk2 b/edk2
index ca407c7246bf405da6d9b1b9d93e5e7f17b4b1f9..7b4a99be8a39c12d3a7fc4b8db9f0eab4ac688d5 160000 (submodule)
--- a/edk2
+++ b/edk2
@@ -1 +1 @@
-Subproject commit ca407c7246bf405da6d9b1b9d93e5e7f17b4b1f9
+Subproject commit 7b4a99be8a39c12d3a7fc4b8db9f0eab4ac688d5