Leftovers from SID bitrate harmonization

There are leftovers from the SID bitrate harmonization effort in the file encoder.c:

#define NUM_BITS_SID_IVAS_4K4      88
#define NUM_BITS_SID_IVAS_7K8      156
#define NUM_BITS_SID_IVAS_9K3      186
#define NUM_BITS_SID_IVAS_10K2     204

They should be updated/removed.