mmc: sdhci: Remove ->platform_init() callback as it's no longer used

The commit 1ef5e49e46b9 ("mmc: sdhci-of-esdhc: add/remove some quirks
according to vendor version") moved sdhci-of-esdhc away from using the
->platform_init() callback.

As it was the only user of it and that it seems reasonable to believe that
it won't be needed again, let's just remove it.

Signed-off-by: Ulf Hansson <[e-mail]>
Acked-by: Adrian Hunter <[e-mail]>

drivers/mmc/host/sdhci-pltfm.c

···
 		host->quirks2 = pdata->quirks2;
 	}
 
-	/*
-	 * Some platforms need to probe the controller to be able to
-	 * determine which caps should be used.
-	 */
-	if (host->ops && host->ops->platform_init)
-		host->ops->platform_init(host);
-
 	platform_set_drvdata(pdev, host);
 
 	return host;

drivers/mmc/host/sdhci.h

···
 	void	(*set_uhs_signaling)(struct sdhci_host *host, unsigned int uhs);
 	void	(*hw_reset)(struct sdhci_host *host);
 	void    (*adma_workaround)(struct sdhci_host *host, u32 intmask);
-	void	(*platform_init)(struct sdhci_host *host);
 	void    (*card_event)(struct sdhci_host *host);
 	void	(*voltage_switch)(struct sdhci_host *host);
 	int	(*select_drive_strength)(struct sdhci_host *host,