clean up dead x86 filter opts code

src/opts/SkBitmapProcState_opts_SSSE3.h

Index: src/opts/SkBitmapProcState_opts_SSSE3.h
diff --git a/src/opts/SkBitmapProcState_opts_SSSE3.h b/src/opts/SkBitmapProcState_opts_SSSE3.h
index c7a9a899236a07161dfcf57d66ece2793e253934..e7799fa2c7196835ecfb42b18fc513ff35c95abf 100644
--- a/src/opts/SkBitmapProcState_opts_SSSE3.h
+++ b/src/opts/SkBitmapProcState_opts_SSSE3.h
@@ -22,12 +22,4 @@ void S32_opaque_D32_filter_DXDY_SSSE3(const SkBitmapProcState& s,
 void S32_alpha_D32_filter_DXDY_SSSE3(const SkBitmapProcState& s,
                                    const uint32_t* xy,
                                    int count, uint32_t* colors);
-
-void S32_D16_filter_DX_SSSE3(const SkBitmapProcState& s,
-                             const uint32_t* xy,
-                             int count, uint16_t* colors);
-void S32_D16_filter_DXDY_SSSE3(const SkBitmapProcState& s,
-                               const uint32_t* xy,
-                               int count, uint16_t* colors);
-
 #endif