ARM: at91: sama5_defconfig: enable CAN PLATFORM driver

CAN_M_CAN_PLATFORM is needed to probe the driver on sama5 platforms
after the driver was split into multiple files.

Signed-off-by: Cristian Birsan <cristian.birsan@microchip.com>

Author: cristibirsan

arch/arm/configs/sama5_defconfig

@@ -60,6 +60,7 @@ CONFIG_VLAN_8021Q=m
 CONFIG_CAN=y
 CONFIG_CAN_AT91=y
 CONFIG_CAN_M_CAN=y
+CONFIG_CAN_M_CAN_PLATFORM=y
 CONFIG_BT=y
 CONFIG_BT_RFCOMM=y
 CONFIG_BT_RFCOMM_TTY=y