drivers: can: mcux: flexcan: failure to handle RTR frames correctly

[henrikbrixandersen]

Describe the bug
The NXP MCUX FlexCAN driver fails to handle CAN remote transmission request frames correctly:

• When installing a RX filter, the driver uses filter->rtr & filter->rtr_mask for setting the filter mask. It should just be using filter->rtr_mask, otherwise filters for non-RTR frames will match RTR frames as well.
• When transmitting a RTR frame, the hardware automatically switches the mailbox used for TX to RX in order to receive the reply. This, however, does not match the Zephyr CAN driver model, where mailboxes are dedicated to either RX or TX. Attempting to reuse the TX mailbox (which was automatically switched to an RX mailbox by the hardware) fails on the first call, after which the mailbox is reset and can be reused for TX. To overcome this, the driver must abort the RX mailbox operation when the hardware performs the TX to RX switch.

To Reproduce
Steps to reproduce the behavior:

1. See above along with the test suite accompanying the fix

Environment (please complete the following information):

• Commit SHA: 62f19cc

Additional context
This was discovered while implementing and testing a fix for #47204.