vop: Add definition of readq/writeq if missing

Include <linux/io-64-nonatomic-lo-hi.h> so that readq/writeq are
replaced by two readl/writel on systems that do not support them.  The
values read/written are pointers which will be 32-bit on 32-bit systems
so the non-atomicity should not matter.

Signed-off-by: Vincent Whitchurch <vincent.whitchurch@axis.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>