MIPS: lantiq: adds static clock for PP32

The Lantiq DSL SoCs have an internal networking processor. Add code to read
the static clock rate.

Signed-off-by: John Crispin <blogic@openwrt.org>
Patchwork: http://patchwork.linux-mips.org/patch/4815/

arch/mips/include/asm/mach-lantiq/lantiq.h

@@ -41,6 +41,7 @@ extern void clk_deactivate(struct clk *clk);
 extern struct clk *clk_get_cpu(void);
 extern struct clk *clk_get_fpi(void);
 extern struct clk *clk_get_io(void);
+extern struct clk *clk_get_ppe(void);
 
 /* find out what bootsource we have */
 extern unsigned char ltq_boot_select(void);