Add encoder control for setting color space

This commit adds encoder side control for vp9 to set color space info
in the output compressed bitstream.

It also amends the "vp9_encoder_params_get_to_decoder" test to verify
the correct color space information is passed from the encoder end to
decoder end.

Change-Id: Ibf5fba2edcb2a8dc37557f6fae5c7816efa52650
diff --git a/vpxenc.c b/vpxenc.c
index e14c5ea..944dfa8 100644
--- a/vpxenc.c
+++ b/vpxenc.c
@@ -442,7 +442,7 @@
   VP8E_SET_MAX_INTER_BITRATE_PCT, VP8E_SET_GF_CBR_BOOST_PCT,
   VP9E_SET_LOSSLESS, VP9E_SET_FRAME_PARALLEL_DECODING, VP9E_SET_AQ_MODE,
   VP9E_SET_FRAME_PERIODIC_BOOST, VP9E_SET_NOISE_SENSITIVITY,
-  VP9E_SET_TUNE_CONTENT,
+  VP9E_SET_TUNE_CONTENT, VP9E_SET_COLOR_SPACE,
   0
 };
 #endif