Make Latency usable with kernel const generics

[Heltion]

cutile::core::Latency currently uses a u32 const parameter:

pub struct Latency<const CYCLES: u32>;

However, kernel entry points currently support only i32 and bool const generics. As a result, latency cannot be exposed as a tunable kernel generic:

#[cutile::entry]
unsafe fn kernel<const LATENCY: u32>(...) {
    load_ptr_tko(..., Latency::<LATENCY>);
}

This fails with:

const generic LATENCY must be i32 or bool, got u32

Changing the kernel generic to i32 also fails because Latency expects u32.

Would it make sense to make Latency use i32, or alternatively support u32 kernel const generics? Either approach would provide a supported way to write:

Latency::<LATENCY>

without branching over hard-coded values such as Latency::<1>, Latency::<2>, etc.