Extend CLPF to chroma.

Objective quality impact (low latency):

PSNR YCbCr:      0.13%     -1.37%     -1.79%
   PSNRHVS:      0.03%
      SSIM:      0.24%
    MSSSIM:      0.10%
 CIEDE2000:     -0.83%

Change-Id: I8ddf0def569286775f0f9d4d4005932766a7fc27
diff --git a/av1/common/onyxc_int.h b/av1/common/onyxc_int.h
index 2bb680a..98f4f51 100644
--- a/av1/common/onyxc_int.h
+++ b/av1/common/onyxc_int.h
@@ -153,7 +153,9 @@
 #if CONFIG_CLPF
   int clpf_numblocks;
   int clpf_size;
-  int clpf_strength;
+  int clpf_strength_y;
+  int clpf_strength_u;
+  int clpf_strength_v;
   uint8_t *clpf_blocks;
 #endif