hikey: Update README to download proper Mali binary

Bug: 38041758
Test: Manual

Change-Id: Ie28bfa601f2de2d05aae6e1f5b4f5b84e5b90ff4
Signed-off-by: Dmitry Shmidt <dimitrysh@google.com>
diff --git a/hikey/README b/hikey/README
index 4995736..9652e20 100644
--- a/hikey/README
+++ b/hikey/README
@@ -5,8 +5,8 @@
 $ repo init -u https://android.googlesource.com/platform/manifest -b master & repo sync -j24
 
 Download and extract HDMI binaries:
-$ wget https://dl.google.com/dl/android/aosp/linaro-hikey-20160226-67c37b1a.tgz
-$ tar xzf linaro-hikey-20160226-67c37b1a.tgz
+$ wget https://dl.google.com/dl/android/aosp/linaro-hikey-20170523-4b9ebaff.tgz
+$ tar xzf linaro-hikey-20170523-4b9ebaff.tgz
 $ ./extract-linaro-hikey.sh
 
 Install mcopy utility: