spi: bcm63xx: use correct format string for printing a resource

With a 64-bit resource_size_t, we get a build warning on bcm63xx_spi_probe:

drivers/spi/spi-bcm63xx.c:565:16: warning: format '%x' expects argument of type 'unsigned int', but argument 3 has type 'resource_size_t {aka long long unsigned int}' [-Wformat=]

As we are printing a resource, we can just use the %pr format
specifier that pretty-prints the address and avoids the warning.

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>
Signed-off-by: Mark Brown <broonie@kernel.org>