[PARISC] Convert parisc_device to use struct resource for hpa

Convert pa_dev->hpa from an unsigned long to a struct resource.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>

Fix up users of ->hpa to use ->hpa.start instead.

Signed-off-by: Matthew Wilcox <willy@parisc-linux.org>

Signed-off-by: Kyle McMartin <kyle@parisc-linux.org>