nvidia/cbootimage: update to latest upstream

Scott Duplichan provided a win32 related fix that
we want to use.

Change-Id: I791b470f9f6c5bf140fc190d290741f35f05d254
Signed-off-by: Patrick Georgi <pgeorgi@google.com>
Reviewed-on: http://review.coreboot.org/7827
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
diff --git a/util/nvidia/cbootimage b/util/nvidia/cbootimage
index 024108e..2eb9a86 160000
--- a/util/nvidia/cbootimage
+++ b/util/nvidia/cbootimage
@@ -1 +1 @@
-Subproject commit 024108eecd2ef03a843cf42e3d45c0db11e4fc75
+Subproject commit 2eb9a86724db0d86c9ab9b6aeca21d1000d74e78