net: rfkill: gpio: prepare for DT and ACPI support

This will add the relevant values like the gpios and the
type in rfkill_gpio_platform_data to the rfkill_gpio_data
structure. It will allow those values to be easily picked
from DT and ACPI tables later.

Signed-off-by: Heikki Krogerus <heikki.krogerus@linux.intel.com>
Acked-by: Rhyland Klein <rklein@nvidia.com>
Reviewed-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Johannes Berg <johannes.berg@intel.com>