msdk: dec: set framerate to the driver only if provided

For example, if framerate 0/1 is provided from upstream, the driver
fails to configure and complain about it.

We can let it go and make the driver assuming framerate itself.

https://bugzilla.gnome.org/show_bug.cgi?id=789752
diff --git a/sys/msdk/gstmsdkdec.c b/sys/msdk/gstmsdkdec.c
index 3dbb03e..62c59a6 100644
--- a/sys/msdk/gstmsdkdec.c
+++ b/sys/msdk/gstmsdkdec.c
@@ -256,8 +256,13 @@
   thiz->param.mfx.FrameInfo.Height = GST_ROUND_UP_32 (info->height);
   thiz->param.mfx.FrameInfo.CropW = info->width;
   thiz->param.mfx.FrameInfo.CropH = info->height;
-  thiz->param.mfx.FrameInfo.FrameRateExtN = info->fps_n;
-  thiz->param.mfx.FrameInfo.FrameRateExtD = info->fps_d;
+
+  /* Set framerate only if provided.
+   * If not, framerate will be assumed inside the driver */
+  if (info->fps_n > 0 && info->fps_d > 0) {
+    thiz->param.mfx.FrameInfo.FrameRateExtN = info->fps_n;
+    thiz->param.mfx.FrameInfo.FrameRateExtD = info->fps_d;
+  }
   thiz->param.mfx.FrameInfo.AspectRatioW = info->par_n;
   thiz->param.mfx.FrameInfo.AspectRatioH = info->par_d;
   thiz->param.mfx.FrameInfo.PicStruct = MFX_PICSTRUCT_PROGRESSIVE;