ASoC: davinci-mcasp: Fix an error handling path in 'davinci_mcasp_probe()'

All error handling paths in this function 'goto err' except this one.

If one of the 2 previous memory allocations fails, we should go through
the existing error handling path. Otherwise there is an unbalanced
pm_runtime_enable()/pm_runtime_disable().

Fixes: dd55ff83 ("ASoC: davinci-mcasp: Add set_tdm_slots() support")
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Acked-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Signed-off-by: Mark Brown <broonie@kernel.org>