Remove dist_8x8 based public API changes

(cherry picked from commit 7de857139db2b0658e52c4ccebadad271c327265)

Change-Id: I2c499828bf11d0b8dc2f5fa8a03f3f491e14bd67

aom/aomcx.h

diff --git a/aom/aomcx.h b/aom/aomcx.h
index 5db659a..558fdf9 100644
--- a/aom/aomcx.h
+++ b/aom/aomcx.h
@@ -638,10 +638,8 @@
 typedef enum {
   AOM_TUNE_PSNR,
   AOM_TUNE_SSIM,
-#ifdef CONFIG_DIST_8X8
   AOM_TUNE_CDEF_DIST,
   AOM_TUNE_DAALA_DIST
-#endif
 } aom_tune_metric;
 
 /*!\cond */