pre-processing directive `I2S_COMM_FORMAT_I2S_MSB` deprecated

[pgislard]

../main/main.c: In function 'app_main':
../main/main.c:64:9: warning: 'I2S_COMM_FORMAT_I2S_MSB' is deprecated [-Wdeprecated-declarations]
         .communication_format = I2S_COMM_FORMAT_I2S_MSB,
         ^