ASoC: max98088: use match_string() helper

ASoC: max98088: use match_string() helper

match_string() returns the index of an array for a matching string,
which can be used instead of open coded variant.

Cc: Liam Girdwood <[email protected]>
Cc: Mark Brown <[email protected]>
Cc: Jaroslav Kysela <[email protected]>
Cc: Takashi Iwai <[email protected]>
Cc: [email protected]
Signed-off-by: Yisheng Xie <[email protected]>
Signed-off-by: Mark Brown <[email protected]>