MPC512X: Cleanup bus clock names.

Signed-off-by: Grzegorz Bernacki <gjb@semihalf.com>
diff --git a/include/asm-ppc/global_data.h b/include/asm-ppc/global_data.h
index c3b5e82..aa6384c 100644
--- a/include/asm-ppc/global_data.h
+++ b/include/asm-ppc/global_data.h
@@ -99,7 +99,7 @@
 	unsigned long	pci_clk;
 #endif
 #if defined(CONFIG_MPC512X)
-	u32 ipb_clk;
+	u32 ips_clk;
 	u32 csb_clk;
 #endif /* CONFIG_MPC512X */
 #if defined(CONFIG_MPC8220)