devicetree.h: Add macros for interrupt specifiers intc

Add the following macros to devicetree.h to get an interrupt
specifier's interrupt controller:

DT_IRQ_INTC_BY_IDX(node_id, idx)
DT_IRQ_INTC_BY_NAME(node_id, name)
DT_IRQ_INTC(node_id)

and their INST variants

DT_INST_INTC_BY_IDX(inst, idx)
DT_INST_INTC_BY_NAME(inst, name)
DT_INST_IRQ(inst)

which use the newly generated _CONTROLLER output from the
previous commit.

Signed-off-by: Bjarki Arge Andreasen <bjarki@arge-andreasen.me>