staging: vt6655: upc.h replace read and write memory functions

Update to the newer memory functions
readb -> ioread8
readw -> ioread16
readl -> ioread32
writeb -> iowrite8
writew -> iowrite16
writel -> iowrite32

Signed-off-by: Malcolm Priestley <tvboxspy@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>