i2c: Use resource_size macro

This replace all instances in the i2c busses tree of
res->end - res->start + 1 with the handy macro resource_size(res)
from ioport.h (coming in from platform_device.h).

This was created with a simple
sed -i -e 's/\([a-z]*\)->end *- *[a-z]*->start *+ *1/resource_size(\1)/g'

Then manually replacing the PXA redefiniton of the same kind
of macro manually. Recompiled some ARM defconfigs I could find to
make a rough test so it shouldn't break anything, though I
couldn't see exactly which configs you need for all the drivers.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Ben Dooks <ben-linux@fluff.org>

drivers/i2c/busses/i2c-au1550.c

@@ -389,7 +389,7 @@ i2c_au1550_probe(struct platform_device *pdev)
 		goto out;
 	}
 
-	priv->ioarea = request_mem_region(r->start, r->end - r->start + 1,
+	priv->ioarea = request_mem_region(r->start, resource_size(r),
 					  pdev->name);
 	if (!priv->ioarea) {
 		ret = -EBUSY;