No SPI3 Interface

[Alex]

Need to add the following code in spi.rs
use hal::gpio::gpioc::{PC10, PC11, PC12}; use hal::gpio:: AF6;

impl Pins<SPI3> for ( PC10<Alternate<AF6, Input<Floating>>>, PC11<Alternate<AF6, Input<Floating>>>, PC12<Alternate<AF6, Input<Floating>>>, ) { const REMAP: bool = false; // TODO REMAP }

[Mathias Koch]

If you open a PR with the changes above, it would go much faster 👍