Correct MPIC order of attachment

If MPIC happens to be a slave interrupt controller (as on Armada38x),
it should be attached after primary interrupt controller.
Thus BUS_PASS_ORDER_LATE was added to default BUS_PASS_INTERRUPT.

This change doesn't affect the cases when MPIC is standalone IC.

Submitted by:  Bartosz Szczepanek <bsz@semihalf.com>
Obtained from: Semihalf
Sponsored by:  Stormshield, Netgate
Reviewed by: loos
Differential revision: https://reviews.freebsd.org/D10715

sys/arm/mv/mpic.c

@@ -398,7 +398,7 @@ static driver_t mv_mpic_driver = {
 static devclass_t mv_mpic_devclass;
 
 EARLY_DRIVER_MODULE(mpic, simplebus, mv_mpic_driver, mv_mpic_devclass, 0, 0,
-    BUS_PASS_INTERRUPT);
+    BUS_PASS_INTERRUPT + BUS_PASS_ORDER_LATE);
 
 #ifndef INTRNG
 int