interrupts-extended helper is completely wrong

[tea]

This property consists of pairs phandle + interrupt-address, and each pair denotes an external interrupt. So, the helper should parse phandle, then interrupt-address for that phandle (using that phandle's #interrupt-cells), and output that pair. Its current behaviour is pretty much useless.
See e.g. from sifive dts:

	clint@2000000 {
			interrupts-extended = <0x07 0x03 0x07 0x07 0x06 0x03 0x06 0x07 0x05 0x03 0x05 0x07 0x04 0x03 0x04 0x07 0x03 0x03 0x03 0x07>;
			reg = <0x00 0x2000000 0x00 0x10000>;
			compatible = "riscv,clint0";
		};

This list means "interrupt 3 of phandle 7", "interrupt 7 of phandle 7", "interrupt 3 of phandle 6" etc.

[repnop]

This is fixed in the ongoing rewrite (see the rewrite branch of the repo), along with a bunch of other issues. I don't have an ETA for the release but it's getting closer. I have the majority of the base work done, so it's mostly adding the various helper structs + other properties then cleaning up the API if need be. I don't think I'm looking to publish any newer versions of the current code at this point since so much is changing between the two, so hold tight and I'll hopefully have a rc version of the rewrite on crates.io in the somewhat near future if all goes well 👍