ASoC: simple-card-utils: add __printf attribute

asoc_simple_card_set_dailink_name() uses devm_kvasprintf() to format
some of its arguments.  Adding a __printf attribute to this function
makes it possible to detect at compile-time errors related to format
strings.

Signed-off-by: Nicolas Iooss <nicolas.iooss_linux@m4x.org>
Signed-off-by: Mark Brown <broonie@kernel.org>