Ignoring test video sequences in the source tree.

Adding /*.ivf and /*.ivf.md5 filename patterns to .gitignore.

Change-Id: I9be9c99023e6b59bcc9cfbb6c9d6cdc8e500fc4f

.gitignore

@@ -3,6 +3,8 @@
 *.d
 *.o
 *~
+/*.ivf
+/*.ivf.md5
 /*-*.mk
 /*.asm
 /*.doxy