ASoC: simple-card: fix regression in clock rate lookup

Commit 7c7b9cf5 ("ASoC: simple-card: fixup cpu_dai_name
clear case") changed the way that "sound-dai" properties are handled,
which leads to the clock frequency not being picked up from the
node that the phandle points to, as correctly identified by gcc
with this warning:

sound/soc/generic/simple-card.c: In function 'asoc_simple_card_sub_parse_of':
sound/soc/generic/simple-card.c:165:7: warning: 'node' may be used uninitialized in this function [-Wmaybe-uninitialized]

This restores the previous behavior by using the node from
of_parse_phandle_with_args() that was previously being
returned from of_parse_phandle().

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Mark Brown <broonie@kernel.org>