ACPI / platform: provide default DMA mask

Most devices are configured for 32-bit DMA addresses.
Setting the mask to 32-bit here removes the need for the
drivers to do it separately.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>