ddr: marvell: a38x: old: Fix some compiler warning of the old code

Fix some compilation warning in the old DDR training code.

Signed-off-by: Marek BehĂșn <kabel@kernel.org>
diff --git a/drivers/ddr/marvell/a38x/old/ddr3_init.h b/drivers/ddr/marvell/a38x/old/ddr3_init.h
index 8cb0886..ad95cc9 100644
--- a/drivers/ddr/marvell/a38x/old/ddr3_init.h
+++ b/drivers/ddr/marvell/a38x/old/ddr3_init.h
@@ -291,7 +291,9 @@
 extern u32 target_freq;
 extern struct hws_tip_config_func_db config_func_info[HWS_MAX_DEVICE_NUM];
 extern u32 clamp_tbl[];
+#if 0
 extern u32 init_freq;
+#endif
 /* list of allowed frequency listed in order of enum hws_ddr_freq */
 extern u32 freq_val[];
 extern u8 debug_training_static;