[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: Adrian Bunk <bunk@kernel.org>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/drivers/char/hvc_rtas.c b/drivers/char/hvc_rtas.c
index bb09413..88590d0 100644
--- a/drivers/char/hvc_rtas.c
+++ b/drivers/char/hvc_rtas.c
@@ -76,7 +76,7 @@
 	.put_chars = hvc_rtas_write_console,
 };
 
-static int hvc_rtas_init(void)
+static int __init hvc_rtas_init(void)
 {
 	struct hvc_struct *hp;