Approach is similar to USB OTG.
STM32L49x and STML4Ax have CAN1 and CAN2.
All others STM32L4xx do only have CAN1.
STM32F72x and STM32F73x are the only F7 devices with only CAN1.
Older families like F1 and F4 have a consistent naming for the CAN
peripherals: CAN when there is only one instance, CAN1/CAN2/CAN2 if
there are multiple instances.
Newer families like L4 and F7 use the name CAN1 even if there is only
one instance. The number of filter banks is incorrect for those.
Affected chips:
* STM32F722
* STM32F723
* STM32F730
* STM32F732
* STM32F733
* STM32L4P5
* STM32L4Q5
* STM32L4R5
* STM32L4R7
* STM32L4R9
* STM32L4S5
* STM32L4S7
* STM32L4S9
* STM32L431
* STM32L432
* STM32L433
* STM32L442
* STM32L443
* STM32L451
* STM32L452
* STM32L462
* STM32L471
* STM32L475
* STM32L476
* STM32L485
* STM32L486