configure: fix mmal build dependencies

The mmal decoders do not depend on the software decoders.

configure

@@ -2494,8 +2494,7 @@ h264_d3d11va_hwaccel_select="h264_decoder"
 h264_dxva2_hwaccel_deps="dxva2"
 h264_dxva2_hwaccel_select="h264_decoder"
 h264_mmal_decoder_deps="mmal"
-h264_mmal_decoder_select="h264_decoder"
-h264_mmal_encoder_deps="mmal"
+h264_mmal_decoder_select="mmal"
 h264_mmal_hwaccel_deps="mmal"
 h264_qsv_hwaccel_deps="libmfx"
 h264_vaapi_hwaccel_deps="vaapi"
@@ -2539,7 +2538,7 @@ mpeg2_d3d11va_hwaccel_select="mpeg2video_decoder"
 mpeg2_dxva2_hwaccel_deps="dxva2"
 mpeg2_dxva2_hwaccel_select="mpeg2video_decoder"
 mpeg2_mmal_decoder_deps="mmal"
-mpeg2_mmal_decoder_select="mpeg2video_decoder"
+mpeg2_mmal_decoder_select="mmal"
 mpeg2_mmal_hwaccel_deps="mmal"
 mpeg2_qsv_hwaccel_deps="libmfx"
 mpeg2_qsv_hwaccel_select="qsvdec_mpeg2"
@@ -2567,7 +2566,7 @@ vc1_d3d11va_hwaccel_select="vc1_decoder"
 vc1_dxva2_hwaccel_deps="dxva2"
 vc1_dxva2_hwaccel_select="vc1_decoder"
 vc1_mmal_decoder_deps="mmal"
-vc1_mmal_decoder_select="vc1_decoder"
+vc1_mmal_decoder_select="mmal"
 vc1_mmal_hwaccel_deps="mmal"
 vc1_qsv_hwaccel_deps="libmfx"
 vc1_qsv_hwaccel_select="qsvdec_vc1"