drivers: can: add can_get_bitrate_{min,max}(), deprecate existing APIs

Since the minimum/maximum supported bitrates are now stored in the common
CAN controller driver configuration struct, retrieving these can no longer
fail.

Add new CAN controller API functions can_get_bitrate_min() and
can_get_bitrate_max() reflecting this and deprecate the existing
can_get_min_bitrate() and can_get_max_bitrate().

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