Add u-boot and flashmap to manifest

Needed to compile the sdk

BUG=b/177367546
TEST=repo init, repo sync
RELEASE_NOTE=None

Change-Id: Ic166cd0884fe17ce6b30a19052cbff4a5e1a594e
Reviewed-on: https://cos-review.googlesource.com/c/cos/manifest/+/34660
Reviewed-by: Dexter Rivera <riverade@google.com>
Tested-by: Robert Kolchmeyer <rkolchmeyer@google.com>
diff --git a/external_full.xml b/external_full.xml
index fb658d3..bb006c1 100644
--- a/external_full.xml
+++ b/external_full.xml
@@ -66,6 +66,13 @@
   <project path="src/platform2"
            name="mirrors/cros/chromiumos/platform2"
            revision="24b587ef5ef0ede247dd005819ac22c6d889b0e4" />
+  <project path="src/third_party/u-boot/files"
+           name="mirrors/cros/chromiumos/third_party/u-boot"
+           revision="4fdd055df627ffe351cfdf03d230eaf63399e1c2" />
+  <project path="src/third_party/flashmap"
+           name="mirrors/cros/chromiumos/third_party/flashmap"
+           revision="2f7b2e16f588dde75a0c9c28175f16b8cb9e11dc" />
+
 
   <!-- COS sources -->
   <project path="src/overlays"