ide: sgiioc4: Staticize ioc4_ide_attach_one()

ioc4_ide_attach_one() is used only in this file.
Fix the following sparse warnings:

drivers/ide/sgiioc4.c:603:5: warning: symbol 'ioc4_ide_attach_one' was not declared. Should it be static?
Signed-off-by: Jingoo Han <jg1.han@samsung.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/ide/sgiioc4.c

@@ -600,7 +600,7 @@ static unsigned int pci_init_sgiioc4(struct pci_dev *dev)
 	return ret;
 }
 
-int ioc4_ide_attach_one(struct ioc4_driver_data *idd)
+static int ioc4_ide_attach_one(struct ioc4_driver_data *idd)
 {
 	/*
 	 * PCI-RT does not bring out IDE connection.