move can.h to drivers/can.h and
create a shim for backward-compatibility.
No functional changes to the headers.
A warning in the shim can be controlled with CONFIG_COMPAT_INCLUDES.
Related to #16539
Signed-off-by: Anas Nashif <anas.nashif@intel.com>
This commit implements a CAN loopback device. This device is used
for testing when no CAN controller is available on the hardware.
Signed-off-by: Alexander Wachter <alexander.wachter@student.tugraz.at>