1360: stm32/rcc: add i2s pll on some f4 micros r=Dirbaio a=xoviat
Adds the i2s pll on some f4 micros.
1361: Executor: Replace unnecessary atomics in runqueue r=Dirbaio a=GrantM11235
Only the head pointer needs to be atomic. The `RunQueueItem` pointers are only loaded and stored, and never concurrently
Co-authored-by: xoviat <xoviat@users.noreply.github.com>
Co-authored-by: Grant Miller <GrantM11235@gmail.com>