mmc: sdhci-pci: add platform data

Add a means of getting platform data for the SDHCI PCI
devices.  The data is stored against the slot not the
device in order to support multi-slot devices.

The data allows platform-specific setup (such as getting
GPIO numbers from firmware or setting up wl12xx for SDIO)
to be done in platform support files instead of the
sdhci-pci driver.

Signed-off-by: Adrian Hunter <adrian.hunter@intel.com>
Signed-off-by: Chris Ball <cjb@laptop.org>

drivers/mmc/host/sdhci-pci-data.c

@@ -0,0 +1,5 @@
+#include <linux/module.h>
+#include <linux/mmc/sdhci-pci-data.h>
+
+struct sdhci_pci_data *(*sdhci_pci_get_data)(struct pci_dev *pdev, int slotno);
+EXPORT_SYMBOL_GPL(sdhci_pci_get_data);