clk: uniphier: add System clock support

Support system clocks for LD4, Pro4, sLD8, Pro5, PXs2/LD6b, LD11, LD20.

Signed-off-by: Masahiro Yamada <yamada.masahiro@socionext.com>
diff --git a/drivers/clk/uniphier/clk-uniphier.h b/drivers/clk/uniphier/clk-uniphier.h
index f9a560e..770a322 100644
--- a/drivers/clk/uniphier/clk-uniphier.h
+++ b/drivers/clk/uniphier/clk-uniphier.h
@@ -50,6 +50,8 @@
 		.rates = {(_reg),},			\
 	}
 
+extern const struct uniphier_clk_data uniphier_pxs2_sys_clk_data;
+extern const struct uniphier_clk_data uniphier_ld20_sys_clk_data;
 extern const struct uniphier_clk_data uniphier_mio_clk_data;
 
 #endif /* __CLK_UNIPHIER_H__ */