atomisp_source_pad_to_stream_id() returns ATOMISP_INPUT_STREAM_GENERAL
unconditionally now. Drop it and directly use ATOMISP_INPUT_STREAM_GENERAL
in its callers.
Signed-off-by: Hans de Goede <hdegoede@redhat.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@kernel.org>