arch: sw_isr: revamp multi-level interrupt architecture

Previously the multi-level irq lookup table is generated by
looping through the devicetree nodes using macros & Kconfig,
which is hard to read and flimsy.

This PR shifts the heavy lifting to devicetree & DT macros such
that an interrupt controller driver, which has its info in the
devicetree, can register itself directly with the multi-level
interrupt architecture, which is more straightforward.

The previous auto-generated look up table with macros is now
moved in a file of its own. A new compatibility Kconfig:
`CONFIG_LEGACY_MULTI_LEVEL_TABLE_GENERATION` is added and
enabled by default to compile the legacy look up table for
interrupt controller drivers that aren't updated to support the
new architecture yet.

Signed-off-by: Yong Cong Sin <ycsin@meta.com>