[POWERPC] hvc_rtas_init() must be __init

This fixes the following section mismatch:

<--  snip  -->

...
WARNING: vmlinux.o(.text+0x2fbca8): Section mismatch in reference from the function .hvc_rtas_init() to the function .devinit.text:.hvc_alloc()
...

<--  snip  -->
Signed-off-by: NAdrian Bunk <bunk@kernel.org>
Signed-off-by: NPaul Mackerras <paulus@samba.org>

drivers/char/hvc_rtas.c

@@ -76,7 +76,7 @@ static struct hv_ops hvc_rtas_get_put_ops = {
 	.put_chars = hvc_rtas_write_console,
 };
 
-static int hvc_rtas_init(void)
+static int __init hvc_rtas_init(void)
 {
 	struct hvc_struct *hp;