ASoC: simple-card: Fix bug of wrong decrement DT node's refcount

DAI links's cpu_of_node's and codec_of_node's refcounts shouldn't
be decremented immediately at the end of the probe() fucntion.
Because we will still use them before the audio card is removed.

Signed-off-by: Xiubo Li <Li.Xiubo@freescale.com>
Signed-off-by: Mark Brown <broonie@kernel.org>