ASoC: tlv320aic3x: Fix null pointer dereference when pdata is not set

Null pointer dereference will occur from *setup = pdata->setup if pdata
is not set. Fix this by moving assignments from pdata inside non-null case.

Thanks to Jiri Slaby <jirislaby@gmail.com> for noticing.

Signed-off-by: Jarkko Nikula <jhnikula@gmail.com>
Cc: Jiri Slaby <jirislaby@gmail.com>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Signed-off-by: Liam Girdwood <lrg@slimlogic.co.uk>