ASoC: wm8940: Remove warning when no plat data present

The lack of platform data in the contemporary Linux
shall not be the reason to display warnings to the
kernel logs.

Signed-off-by: Lukasz Majewski <lukma@denx.de>
Acked-by: Charles Keepax <ckeepax@opensource.cirrus.com>
Link: https://lore.kernel.org/r/20221216094624.3849278-1-lukma@denx.de
Signed-off-by: Mark Brown <broonie@kernel.org>