tty/hvc_opal: Fix debug function name

udbg_init_debug_opal() should be udbg_init_debug_opal_raw() as
the caller in arch/powerpc/kernel/udbg.c expects
Signed-off-by: NBenjamin Herrenschmidt <benh@kernel.crashing.org>

drivers/tty/hvc/hvc_opal.c

@@ -401,7 +401,7 @@ void __init hvc_opal_init_early(void)
 }
 
 #ifdef CONFIG_PPC_EARLY_DEBUG_OPAL_RAW
-void __init udbg_init_debug_opal(void)
+void __init udbg_init_debug_opal_raw(void)
 {
 	u32 index = CONFIG_PPC_EARLY_DEBUG_OPAL_VTERMNO;
 	hvc_opal_privs[index] = &hvc_opal_boot_priv;