ASoC: mid-x86: Remove redundant platform_set_drvdata()

Commit 0998d06310 (device-core: Ensure drvdata = NULL when no
driver is bound) removes the need to set driver data field to
NULL.

Signed-off-by: Sachin Kamat <sachin.kamat@linaro.org>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

sound/soc/mid-x86/mfld_machine.c

@@ -425,7 +425,6 @@ static int snd_mfld_mc_remove(struct platform_device *pdev)
 	free_irq(platform_get_irq(pdev, 0), mc_drv_ctx);
 	snd_soc_unregister_card(&snd_soc_card_mfld);
 	kfree(mc_drv_ctx);
-	platform_set_drvdata(pdev, NULL);
 	return 0;
 }