ARM: dts: at91: sama5d2: fix CAN message ram offset and size

ARM: dts: at91: sama5d2: fix CAN message ram offset and size

CAN0 and CAN1 instances share the same message ram configured
at 0x210000 on sama5d2 Linux systems.
According to current configuration of CAN0, we need 0x1c00 bytes
so that the CAN1 don't overlap its message ram:
64 x RX FIFO0 elements => 64 x 72 bytes
32 x TXE (TX Event FIFO) elements => 32 x 8 bytes
32 x TXB (TX Buffer) elements => 32 x 72 bytes
So a total of 7168 bytes (0x1C00).

Fix offset to match this needed size.
Make the CAN0 message ram ioremap match exactly this size so that is
easily understandable.  Adapt CAN1 size accordingly.

Fixes: bc6d5d7666b7 ("ARM: dts: at91: sama5d2: add m_can nodes")
Reported-by: Dan Sneddon <dan.sneddon@microchip.com>
Signed-off-by: Nicolas Ferre <nicolas.ferre@microchip.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@bootlin.com>
Tested-by: Cristian Birsan <cristian.birsan@microchip.com>
Cc: stable@vger.kernel.org # v4.13+
Link: https://lore.kernel.org/r/20201203091949.9015-1-nicolas.ferre@microchip.com