dpaa2-switch: request all interrupts sources on the DPSW

Request all interrupt sources to be read and then cleared on the DPSW
object. In the next patches we'll also add support for treating other
interrupts.

Signed-off-by: Ioana Ciornei <ioana.ciornei@nxp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>