sbc: Declare and implement sbc_init_msbc
sbc: Add support for mSBC frame header

Traditionnal SBC frame header describe encoding parameters for each frame: nr
of blocks, subbands, allocation method, and bitpool. In mSBC, only one
combination of parameter is defined. That combination cannot be expressed using
a traditionnal SBC header. Because of this, a specific header is defined with
0xAD followed by two reserved zero bytes.
sbc: Update sbcdec for msbc
sbc: Update sbcenc for msbc
sbc: Update sbcinfo for msbc
sbc: bump version number
Add sample.au
Add test scripts
mmx: call emms after each assembler routine