[POWERPC] RTAS delay, fix module build breaks

Export both news RTAS delay functions, and change the scanlog module to
use the new delay functions.

Signed-off-by: John Rose <johnrose@austin.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>
diff --git a/arch/powerpc/kernel/rtas.c b/arch/powerpc/kernel/rtas.c
index fd15e3e..17dc791 100644
--- a/arch/powerpc/kernel/rtas.c
+++ b/arch/powerpc/kernel/rtas.c
@@ -797,6 +797,7 @@
 EXPORT_SYMBOL(rtas_data_buf);
 EXPORT_SYMBOL(rtas_data_buf_lock);
 EXPORT_SYMBOL(rtas_busy_delay_time);
+EXPORT_SYMBOL(rtas_busy_delay);
 EXPORT_SYMBOL(rtas_get_sensor);
 EXPORT_SYMBOL(rtas_get_power_level);
 EXPORT_SYMBOL(rtas_set_power_level);