armv7(float): Optimize decode usecase using NE10 library

Optimize opus decode (float only) use case using ARM NE10.
Mainly effects opus_ifft and ctl_mdct_backward and related
functions.

Work based on previous Encode optimization using ARM NE10
library. See previous commit for details on how to enable
this.

Signed-off-by: Timothy B. Terriberry <tterribe@xiph.org>
13 files changed