vpx_scale: add missing rtcd + vpx_scale includes

silences missing prototype warnings

Change-Id: I33320f66c789b8c5c51d69f9dc0e017f9e06b0d0
diff --git a/vpx_scale/generic/gen_scalers.c b/vpx_scale/generic/gen_scalers.c
index 995c45b..dab324e 100644
--- a/vpx_scale/generic/gen_scalers.c
+++ b/vpx_scale/generic/gen_scalers.c
@@ -8,7 +8,7 @@
  *  be found in the AUTHORS file in the root of the source tree.
  */
 
-
+#include "./vpx_scale_rtcd.h"
 #include "vpx_scale/vpx_scale.h"
 #include "vpx_mem/vpx_mem.h"
 /****************************************************************************
diff --git a/vpx_scale/generic/vpx_scale.c b/vpx_scale/generic/vpx_scale.c
index 089e673..15e4ba8 100644
--- a/vpx_scale/generic/vpx_scale.c
+++ b/vpx_scale/generic/vpx_scale.c
@@ -22,6 +22,7 @@
 ****************************************************************************/
 #include "./vpx_scale_rtcd.h"
 #include "vpx_mem/vpx_mem.h"
+#include "vpx_scale/vpx_scale.h"
 #include "vpx_scale/yv12config.h"
 
 typedef struct {
diff --git a/vpx_scale/generic/yv12extend.c b/vpx_scale/generic/yv12extend.c
index 13ee3e9..086e2f3 100644
--- a/vpx_scale/generic/yv12extend.c
+++ b/vpx_scale/generic/yv12extend.c
@@ -10,6 +10,7 @@
 
 #include <assert.h>
 #include "./vpx_config.h"
+#include "./vpx_scale_rtcd.h"
 #include "vpx/vpx_integer.h"
 #include "vpx_mem/vpx_mem.h"
 #include "vpx_ports/mem.h"