ASoC: wm8753: Skip noop reconfiguration of DAI mode

This patch makes it possible to set DAI mode to its currently applied
value even if codec is active. This is necessary to allow

aplay -t raw -r 44100 -f S16_LE -c 2 < /dev/urandom &
alsactl store -f backup.state
alsactl restore -f backup.state

to work without returning errors. This patch is based on a patch sent
by Klaus Kurzmann <mok@fluxnetz.de>.

Signed-off-by: Timo Juhani Lindfors <timo.lindfors@iki.fi>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Cc: stable@vger.kernel.org