clk: rockchip: Optimize PLL table memory usage

Before the change: The sizeof rk3568_pll_rates = 2544
Use union: The sizeof rk3568_pll_rates = 1696

In future Soc, more PLL types will be added, and the
rockchip_pll_rate_table will add more members,
and the space savings will be even more pronounced
by using union.

Signed-off-by: Elaine Zhang <zhangqing@rock-chips.com>
Link: https://lore.kernel.org/r/20210511090726.15146-1-zhangqing@rock-chips.com
Signed-off-by: Heiko Stuebner <heiko@sntech.de>

Author: Elaine Zhang

drivers/clk/rockchip/clk.h

@@ -271,17 +271,24 @@ struct rockchip_clk_provider {
 
 struct rockchip_pll_rate_table {
 	unsigned long rate;
-	unsigned int nr;
-	unsigned int nf;
-	unsigned int no;
-	unsigned int nb;
-	/* for RK3036/RK3399 */
-	unsigned int fbdiv;
-	unsigned int postdiv1;
-	unsigned int refdiv;
-	unsigned int postdiv2;
-	unsigned int dsmpd;
-	unsigned int frac;
+	union {
+		struct {
+			/* for RK3066 */
+			unsigned int nr;
+			unsigned int nf;
+			unsigned int no;
+			unsigned int nb;
+		};
+		struct {
+			/* for RK3036/RK3399 */
+			unsigned int fbdiv;
+			unsigned int postdiv1;
+			unsigned int refdiv;
+			unsigned int postdiv2;
+			unsigned int dsmpd;
+			unsigned int frac;
+		};
+	};
 };
 
 /**