common: Add new clk command

Command provides just dump subcommand for showing clock
frequencies in a soc.

Signed-off-by: Michal Simek <michal.simek@xilinx.com>
Acked-by: Stefano Babic <sbabic@denx.de>
diff --git a/include/clk.h b/include/clk.h
new file mode 100644
index 0000000..df4570c
--- /dev/null
+++ b/include/clk.h
@@ -0,0 +1,6 @@
+#ifndef _CLK_H_
+#define _CLK_H_
+
+int soc_clk_dump(void);
+
+#endif /* _CLK_H_ */