3rdparty/chromeec: Add Chrome EC firmware sources

Note that this is a manually added commit id (to get the CrEC fixes in
that are necessary for building outside cros_sdk), so it will probably

Change-Id: Idc15cf268c663ae49b209b92b198c9a4d122c7e3
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://review.coreboot.org/13546
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/.gitmodules b/.gitmodules
index 5990f2d..b8f28cd 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -12,3 +12,6 @@
 [submodule "arm-trusted-firmware"]
 	path = 3rdparty/arm-trusted-firmware
 	url = ../arm-trusted-firmware.git
+[submodule "3rdparty/chrome-ec"]
+	path = 3rdparty/chromeec
+	url = ../chrome-ec.git