Compilation failing on nightly-2022-03-28 and newer for users of pin_alias! macro

[TDHolmes]

To reproduce:

1. rustup default nightly-2022-03-28 && rustup target add thumbv6m-none-eabi
2. cd atsamd/boards/feather_m0
3. cargo check --example=blinky_basic

I expect this to compile properly like on stable, instead it fails to compile with:

error: no rules expected the token `red_led`
  --> examples/blinky_basic.rs:30:52
   |
30 |     let mut red_led: bsp::RedLed = pin_alias!(pins.red_led).into();
   |                                                    ^^^^^^^ no rules expected this token in macro call

rust issue: rust-lang/rust#95569

[TDHolmes]

Rust issue closed, should be available in tomorrow's nightly

[TDHolmes]

CI now passes on latest nightly 🎉