powerpc/85xx: add SerDes bank 4 lanes

Only some chips have four SerDes banks, so don't define lanes for a bank
that doesn't exist.

Signed-off-by: Timur Tabi <timur@tabi.org>
Signed-off-by: Andy Fleming <afleming@freescale.com>
diff --git a/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c b/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c
index 825a292..b621adf 100644
--- a/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c
+++ b/arch/powerpc/cpu/mpc85xx/fsl_corenet_serdes.c
@@ -103,6 +103,10 @@
 	{ 22, 168, FSL_SRDS_BANK_3 },
 	{ 23, 169, FSL_SRDS_BANK_3 },
 #endif
+#if SRDS_MAX_BANK > 3
+	{ 24, 175, FSL_SRDS_BANK_4 },
+	{ 25, 176, FSL_SRDS_BANK_4 },
+#endif
 };
 
 int serdes_get_lane_idx(int lane)