nfc: s3fwrn5: let core configure the interrupt trigger

If interrupt trigger is not set when requesting the interrupt, the core
will take care of reading trigger type from Devicetree.  There is no
point to do it in the driver.

Signed-off-by: Krzysztof Kozlowski <krzk@kernel.org>
Link: https://lore.kernel.org/r/20201210211824.214949-1-krzk@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>