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