[WATCHDOG] pci: use pci_ioremap_bar() in drivers/watchdog

Use the newly introduced pci_ioremap_bar() function in drivers/watchdog.
pci_ioremap_bar() just takes a pci device and a bar number, with the goal
of making it really hard to get wrong, while also having a central place
to stick sanity checks.


Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Wim Van Sebroeck <wim@iguana.be>