platform: Make platform resource input parameters const

Make the platform resource input parameters of platform_device_add_resources()
and platform_device_register_simple() const, as the resources are copied and
never modified.

Signed-off-by: Geert Uytterhoeven <geert@linux-m68k.org>
Acked-by: Greg Kroah-Hartman <gregkh@suse.de>