soc: ixp4xx: fix printing resources

When compile-testing with 64-bit resource_size_t, gcc reports an invalid
printk format string:

In file included from include/linux/dma-mapping.h:7,
                 from drivers/soc/ixp4xx/ixp4xx-npe.c:15:
drivers/soc/ixp4xx/ixp4xx-npe.c: In function 'ixp4xx_npe_probe':
drivers/soc/ixp4xx/ixp4xx-npe.c:694:18: error: format '%x' expects argument of type 'unsigned int', but argument 4 has type 'resource_size_t' {aka 'long long unsigned int'} [-Werror=format=]
    dev_info(dev, "NPE%d at 0x%08x-0x%08x not available\n",

Use the special %pR format string to print the resources.

Fixes: 0b458d7b ("soc: ixp4xx: npe: Pass addresses as resources")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>