pata_of_platform: fix compile error

I failed to include <linux/libata.h>, causing this error:

  drivers/ata/pata_of_platform.c:93: error: 'ata_platform_remove_one' undeclared here (not in a function)
Signed-off-by: Brian Norris <computersforpeace@gmail.com>
Signed-off-by: Jeff Garzik <jgarzik@redhat.com>

drivers/ata/pata_of_platform.c

@@ -14,6 +14,7 @@
 #include <linux/of_address.h>
 #include <linux/platform_device.h>
 #include <linux/ata_platform.h>
+#include <linux/libata.h>
 
 static int __devinit pata_of_platform_probe(struct platform_device *ofdev)
 {