libva (VAAPI) has changed their API. Use the legacy API.

Validated as working by Frank P.

Fixes #11631

Signed-off-by: Gary Buhrmaster <gary.buhrmaster@gmail.com>
Signed-off-by: Jean-Yves Avenard <jyavenard@mythtv.org>

mythtv/libs/libmythtv/vaapicontext.h

@@ -4,6 +4,10 @@
 extern "C" {
 #include "libavcodec/vaapi.h"
 }
+#include "va/va_version.h"
+#if VA_CHECK_VERSION(0,34,0)
+#include "va/va_compat.h"
+#endif
 #include "va/va_x11.h"
 #include "va/va_glx.h"
 #include "videocolourspace.h"