staging: comedi: 8253: mmio address is a void __iomem *

The inline functions for accessing a memory mapped 8254 device
are using a void * for the 'base_address' of the device. Memory
mapped io using the read/write functions should be using a
void __iomem * for the address.

Fixing these exposed a couple other void * / void __iomem *
issues in the ni_labpc driver.

This fixes a number of sparse warnings like:

  warning: incorrect type in argument 2 (different address spaces)
     expected void volatile [noderef] <asn:2>*addr
     got void *

  warning: incorrect type in argument 1 (different address spaces)
     expected void const volatile [noderef] <asn:2>*addr
     got void *<noident>

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Cc: Ian Abbott <abbotti@mev.co.uk>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>