drivers: can: remove CAN_HAS_CANFD Kconfig helper

Remove the CAN_HAS_CANFD Kconfig helper symbol in order to allow enabling
CAN-FD support in the API regardless of driver support.

Change default to CAN-FD support being disabled and have samples and tests
that require CAN-FD support turn it on. This aligns the default
configuration across CAN controller drivers regardless of their
capabilities.

The rationale behind this is that we are starting to see MCUs with multiple
CAN controllers, some CAN-FD compatible, some not (e.g. NXP i.MX RT1060 and
FPGAs). Automatically enabling CAN-FD support based on the presence of a
CAN-FD capable CAN controller leads to different application default
settings based on the CAN controller(s) in use.

Signed-off-by: Henrik Brix Andersen <hebad@vestas.com>
9 files changed