audio/polyphone: fix build on big-endian

../polyphone-2.4.1/sources/core/input/sfark/sfarkextractor2.cpp:293:5: error: use of undeclared identifier 'bioP'

293 |     INBITS(w, n);
    |     ^

../polyphone-2.4.1/sources/core/input/sfark/sfarkextractor2.cpp:62:5: note: expanded from macro 'INBITS'

62 |     CHECK_INBUFFER                              \
   |     ^

../polyphone-2.4.1/sources/core/input/sfark/sfarkextractor2.cpp:76:9: note: expanded from macro 'CHECK_INBUFFER'

76 |     if (bioP == BIOBUFSIZE)                       \
   |         ^

../polyphone-2.4.1/sources/core/input/sfark/sfarkextractor2.cpp:293:5: error: use of undeclared identifier 'bioWholeBlocks'; did you mean '_bioWholeBlocks'?
../polyphone-2.4.1/sources/core/input/sfark/sfarkextractor2.cpp:62:5: note: expanded from macro 'INBITS'

62 |     CHECK_INBUFFER                              \
   |     ^

../polyphone-2.4.1/sources/core/input/sfark/sfarkextractor2.cpp:78:5: note: expanded from macro 'CHECK_INBUFFER'

78 |     bioWholeBlocks++;                           \
   |     ^

../polyphone-2.4.1/sources/core/input/sfark/sfarkextractor2.h:411:12: note: '_bioWholeBlocks' declared here

411 |     int    _bioWholeBlocks;                     // Count blocks read from disk
    |            ^