Currently it is tedious to know the level of an interrupt for
a node in C. One would have to go through a very complex and
error prone macros to check if there's a parent interrupt
controller & if the controller has an interrupt number and thus
not a pseudo interrupt controller like the one found in
`rv32m1`. The level of a node is required to encode the
Zephyr's multi-level interrupt number
Since it is easier to do it in the `gen_defines` script, let's
do the heavy lifting there so that we can introduce new DT
macros to get the interrupt level very easily later.
Signed-off-by: Yong Cong Sin <ycsin@meta.com>
450a66fa36
