ALSA: 6fire: Convert byte_rev_table uses to bitrev8

Use the inline function instead of directly indexing the array.

This allows some architectures with hardware instructions
for bit reversals to eliminate the array.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Merge branch 'for-next'