ehci: msm: Add missing platdata

platdata_auto_alloc_size was not initialized in structure.
Caused null pointer dereference when configuring device as
gadget.

Signed-off-by: Ramon Fried <ramon.fried@gmail.com>

drivers/usb/host/ehci-msm.c

@@ -167,5 +167,6 @@ U_BOOT_DRIVER(usb_ehci) = {
 	.remove = ehci_usb_remove,
 	.ops	= &ehci_usb_ops,
 	.priv_auto_alloc_size = sizeof(struct msm_ehci_priv),
+	.platdata_auto_alloc_size = sizeof(struct usb_platdata),
 	.flags	= DM_FLAG_ALLOC_PRIV_DMA,
 };