Implementation of the FlexCAN1 and FlexCAN2 peripherals for the  NXP i.MX RT 1060 processor.

Includes APIs for initializing the peripherals, setting the clock source, setting mailbox receive filters, setting mailbox FIFO functionality, and receiving and transmitting frames.

The FlexCAN3 peripheral is not implemented.

- Remove StandardId and ExtendedId structs in favor of embedded-hal
- convert TryFrom to From for FlexCanMailboxCSCode

- added bounds checks on StandardID and ExtendedID for creation of IdReg

- improved Error descriptiveness

- added docs to Frame timestamp field

- Update Cargo.toml

- fixed clock configuration in builder method and removed set_ccm_ccg method

- removed unused `instance` method

- removed duplicated `set_fifo_filter` method in favor of single method that accepts a `FlexCanFilter` as arg

- removed dead code

Implementation of the FlexCAN1 and FlexCAN2 peripherals for the  NXP i.MX RT 1060 processor.

Includes APIs for initializing the peripherals, setting the clock source, setting mailbox receive filters, setting mailbox FIFO functionality, and receiving and transmitting frames.

The FlexCAN3 peripheral is not implemented.

…into dev/can

We need properly-formmated code to pass CI.

It can't automatically fix all the issues, but the remaining fixes are
straightforward.

Use the fact that a bool is either a zero or a one to simplify the
filter value. Warned by clippy, and implemented by hand.

See PR Issue: imxrt-rs#122 (comment)