CBMEM console: Fix CAR migration step

With the change it becomes irrelevant if memcpy() car.global_data or
cbmemc_reinit() is done first.

Change-Id: Ie479eef346c959e97dcc55861ccb0db1321fb7b2
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/8032
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@google.com>
Tested-by: build bot (Jenkins)

src/arch/riscv/include/arch/early_variables.h

@@ -29,6 +29,7 @@
 #define CAR_MIGRATE(migrate_fn_)
 static inline void *car_get_var_ptr(void *var) { return var; }
 #define car_get_var(var) (var)
+#define car_sync_var(var) (var)
 #define car_set_var(var, val) do { (var) = (val); } while (0)
 static inline void car_migrate_variables(void) { }