common: Move get_OPB_freq() and get_PCI_freq() to PPC header

These should not be in common.h. Move the to an arch-specific header.

Signed-off-by: Simon Glass <sjg@chromium.org>
diff --git a/arch/powerpc/include/asm/ppc4xx.h b/arch/powerpc/include/asm/ppc4xx.h
index b8b0ff9..30e6559 100644
--- a/arch/powerpc/include/asm/ppc4xx.h
+++ b/arch/powerpc/include/asm/ppc4xx.h
@@ -289,6 +289,9 @@
 
 int ppc4xx_pci_sync_clock_config(u32 async);
 
+unsigned long get_OPB_freq(void);
+unsigned long get_PCI_freq(void);
+
 #endif	/* __ASSEMBLY__ */
 
 /* for multi-cpu support */
diff --git a/include/common.h b/include/common.h
index 6dd0d2f..8b64407 100644
--- a/include/common.h
+++ b/include/common.h
@@ -649,10 +649,6 @@
 #if defined(CONFIG_MPC5xxx)
 int	prt_mpc5xxx_clks (void);
 #endif
-#ifdef CONFIG_4xx
-ulong	get_OPB_freq (void);
-ulong	get_PCI_freq (void);
-#endif
 #if defined(CONFIG_S3C24X0) || \
     defined(CONFIG_LH7A40X) || \
     defined(CONFIG_EP93XX)