Add d_can instances to aliases node to get the D_CAN instance number
from the driver. To initialize D_CAN message RAM, corresponding instance
number is required.

To initialize instance 0 message RAM then 0x1 should be written and for
instance 1 message RAM, 0x2 should be written to control module register.

With device-tree framework ip instance number is "-1" by default for all
instances. To get device id/instance number then modules should be added
to DT "aliases" node. of_alias_get_id() gives the device id number based
on number of alias nodes present in "aliases node".
Signed-off-by: AnilKumar Ch <anilkumar@ti.com>
Acked-by: Marc Kleine-Budde <mkl@pengutronix.de>
Signed-off-by: Benoit Cousson <benoit.cousson@linaro.org>