avcodec/dcaenc: Do not abort process in case of bitrate deficit

avcodec/dcaenc: Do not abort process in case of bitrate deficit

Old behaviour - abort if at least one subband has 1bit quantizer
and consumed_bits still greater than frame_bits size. It was
a bit strange - we still could reduce bits consumption by reducing
SNR for other subbands. Same strange logic with upper threshold -
stop bits allocation if at least one subband reach 26bits.

New behaviour - if consumed_bits greater than frame_bits and all
subbands has 1 bit quantizer we restart bits allocation and allow
zero subbands.