Update intel-microcode submodule to tag microcode-20230808

Updating from commit id 6f36ebd:
2023-06-13 16:09:19 -0600 - (microcode-20230613 Release)

to commit id 6788bb0:
2023-08-08 12:04:21 -0600 - (microcode-20230808 Release)

This brings in 1 new commits:
6788bb0 microcode-20230808 Release

https://github.com/intel/Intel-Linux-Processor-Microcode-Data-Files/releases/tag/microcode-20230808

Change-Id: I2885b0189c4b6e68dc5ae6b2a3f809280ed4507a
Signed-off-by: Paul Menzel <pmenzel@molgen.mpg.de>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/77132
Reviewed-by: Nico Huber <nico.h@gmx.de>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Sean Rhodes <sean@starlabs.systems>
Reviewed-by: Elyes Haouas <ehaouas@noos.fr>
Reviewed-by: Matt DeVillier <matt.devillier@gmail.com>
Reviewed-by: Felix Singer <service+coreboot-gerrit@felixsinger.de>
diff --git a/3rdparty/intel-microcode b/3rdparty/intel-microcode
index 6f36ebd..6788bb0 160000
--- a/3rdparty/intel-microcode
+++ b/3rdparty/intel-microcode
@@ -1 +1 @@
-Subproject commit 6f36ebde4519f8a21a047c3433b80a3fb41361e1
+Subproject commit 6788bb07eb5f9e9b83c31ea1364150fe898f450a