watchdog: orion_wdt: Use %pa to print 'phys_addr_t'

When building an ARM multi_v7_defconfig with LPAE option selected we get the
following build warning:

drivers/watchdog/orion_wdt.c:272:2: warning: format '%x' expects argument of type 'unsigned int', but argument 4 has type 'phys_addr_t' [-Wformat=]

Fix it by using %pa to print 'phys_addr_t'.

Reported-by: Olof's autobuilder <build@lixom.net>
Reviewed-by: Guenter Roeck <linux@roeck-us.net>
Acked-by: Ezequiel Garcia <ezequiel.garcia@free-electrons.com>
Acked-by: Wim Van Sebroeck <wim@iguana.be>
Signed-off-by: Fabio Estevam <fabio.estevam@freescale.com>
Signed-off-by: Jason Cooper <jason@lakedaemon.net>