ASoC: sst-bxt-da7219_max98357a: fix obsoleted initializer for array

ASoC: sst-bxt-da7219_max98357a: fix obsoleted initializer for array

Smatch reports below warnings:

    bxt_da7219_max98357a.c:352:9: warning: obsolete array initializer,
    use C99 syntax

An earlier commit cleaned up similar warnings, however, a recent
commit 2167ba6f3586175 ("ASoC: Intel: Add DMIC channel constraint for
bxt machine") re-introduced the older initializer style. So fix
this warning to make the code consistent.

Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Takashi Sakamoto <o-takashi@sakamocchi.jp>
Acked-by: Vinod Koul <vinod.koul@intel.com>
Signed-off-by: Mark Brown <broonie@kernel.org>