ASoC: uniperf: Staticise local symbols

uni_player_dai_ops is not used outside of this file so it should be static.
Fixes the following sparse warning:

	sound/soc/sti/uniperif_player.c:959:30: warning: symbol
		'uni_player_dai_ops' was not declared. Should it be static?

Signed-off-by: Lars-Peter Clausen <lars@metafoo.de>
Acked-by: Arnaud Pouliquen <arnaud.pouliquen@st.com>
Signed-off-by: Mark Brown <broonie@kernel.org>