Add intel-microcode submodule repository

Change-Id: Icc5ac0a8033e371ecf2b4b28ba45dab961e86b3f
Signed-off-by: Philipp Deppenwiese <zaolin.daisuki@gmail.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/33550
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Arthur Heymans <arthur@aheymans.xyz>
Reviewed-by: Lijian Zhao <lijian.zhao@intel.com>
diff --git a/.gitmodules b/.gitmodules
index 78e2c88..e18f0dc 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -29,3 +29,8 @@
 [submodule "opensbi"]
 	path = 3rdparty/opensbi
 	url = ../opensbi.git
+[submodule "intel-microcode"]
+	path = 3rdparty/intel-microcode
+	url = ../intel-microcode.git
+	update = none
+	ignore = dirty
diff --git a/3rdparty/intel-microcode b/3rdparty/intel-microcode
new file mode 160000
index 0000000..1dd14da
--- /dev/null
+++ b/3rdparty/intel-microcode
@@ -0,0 +1 @@
+Subproject commit 1dd14da6d1ea5cfbd95923653f31c04aac3aa655