Add SPI Methods trait and vtable

[CohenArthur]

This will need a few refactorings, but I'd like to get the first basic implementation reviewed. This is super similar to what's being done in FileOperations and would probably deserve some code factoring (for example, a general macro to declare "vtables" and their usage in a generic trait.

I also wonder if this part

         match T::TO_USE.probe {
            false => spi_driver.probe = None,
            true => spi_driver.probe = Some(DriverRegistration::probe_wrapper::<T>),
        }
        match T::TO_USE.remove {
            false => spi_driver.remove = None,
            true => spi_driver.remove = Some(DriverRegistration::remove_wrapper::<T>),
        }
        match T::TO_USE.shutdown {
            false => spi_driver.shutdown = None,
            true => spi_driver.shutdown = Some(DriverRegistration::shutdown_wrapper::<T>),
        }

would benefit from some sort of macro or private function? Since it's very repetitive code, we could do something like

fn get_wrapper<F>(usage: bool, fn: F) -> Option<F> {
    match usage {
        false => None,
        true => Some(F),
    }
}

Please let me know what you guys think :)

[Skallwar]

Can you provide an example of how to use this?

[Skallwar]

And how it works 😅

[Skallwar]

get_wrapper refactor is a good idea