avfilter/vf_(guided|program_opencl): Add missing dynamic inputs flag

The code for inserting inpads can't be reached by ff_vsrc_openclsrc
(unsurprising given that it is a source filter), so it didn't get
the flag.

Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavfilter/vf_guided.c

@@ -500,6 +500,7 @@ const AVFilter ff_vf_guided = {
     .activate        = activate,
     .inputs          = NULL,
     .outputs         = guided_outputs,
-    .flags           = AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC | AVFILTER_FLAG_SLICE_THREADS,
+    .flags           = AVFILTER_FLAG_DYNAMIC_INPUTS | AVFILTER_FLAG_SLICE_THREADS |
+                       AVFILTER_FLAG_SUPPORT_TIMELINE_GENERIC,
     .process_command = process_command,
 };

libavfilter/vf_program_opencl.c

@@ -367,6 +367,7 @@ const AVFilter ff_vf_program_opencl = {
     .description    = NULL_IF_CONFIG_SMALL("Filter video using an OpenCL program"),
     .priv_size      = sizeof(ProgramOpenCLContext),
     .priv_class     = &program_opencl_class,
+    .flags          = AVFILTER_FLAG_DYNAMIC_INPUTS,
     .preinit        = &program_opencl_framesync_preinit,
     .init           = &program_opencl_init,
     .uninit         = &program_opencl_uninit,