command: Fix handling of buffer passing in args[] on 64bit mcu

If the buffer pointer can't fit in a uint32_t then pass a relative
buffer offset instead.  This fixes buffer handling on 64bit linux
mcus.

Signed-off-by: Kevin O'Connor <kevin@koconnor.net>

src/linux/console.c

@@ -131,6 +131,12 @@ static struct task_wake console_wake;
 static uint8_t receive_buf[4096];
 static int receive_pos;
 
+void *
+console_receive_buffer(void)
+{
+    return receive_buf;
+}
+
 // Process any incoming commands
 void
 console_task(void)