rockchip: clk: clk_rk3568: Add CLK_PCIEPHY2_REF support

Add dummy support for the CLK_PCIEPHY2_REF clock.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>
diff --git a/drivers/clk/rockchip/clk_rk3568.c b/drivers/clk/rockchip/clk_rk3568.c
index 6bdd96f..0df82f5 100644
--- a/drivers/clk/rockchip/clk_rk3568.c
+++ b/drivers/clk/rockchip/clk_rk3568.c
@@ -427,6 +427,7 @@
 		break;
 	case CLK_PCIEPHY0_REF:
 	case CLK_PCIEPHY1_REF:
+	case CLK_PCIEPHY2_REF:
 		return 0;
 	default:
 		return -ENOENT;