ASoC: atmel: Remove unnecessary function call

The function platform_set_drvdata copies the value the variable
card to card->dev->driver_data, then the address of &pdev->dev is
assigned to card->dev in atmel_pdmic_asoc_card_init, but when
calling snd_soc_register_card,the function
dev_set_drvdata(card->dev, card) will do the same copy operation,
so i think that the former copy operation can be removed.

Signed-off-by: Peng Donglin <dolinux.peng@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>