codecs: disable incompatible ARM assembly for Cortex-M

Some assembly routines don't work on Thumb as-is. For now
just disable these so the codecs compile.

Affected codecs:

- libflac
- libmad
- libspeex
- libtta
- libwavpack

A few DSP routines need to be disabled for the same reason:

- crossfeed_process
- crossfeed_meier_process
- resample_hermite
- filter_process
- sample_output_stereo

Change-Id: I277e0719652096745a19a7e2b597eff32d8e1553

lib/rbcodec/dsp/dsp_sample_output.c

@@ -63,7 +63,9 @@ void sample_output_mono(struct sample_io_data *this,
     }
     while (--count > 0);
 }
+#endif /* CPU */
 
+#if (!defined(CPU_COLDFIRE) && !defined(CPU_ARM)) || defined(CPU_ARM_MICRO)
 /* write stereo internal format to output format */
 void sample_output_stereo(struct sample_io_data *this,
                           struct dsp_buffer *src, struct dsp_buffer *dst)