clk: rockchip: rk3568: Add dummy support for GMAC speed clocks

Pine64 Quartz64 boards DT reference SCLK_GMAC1_RGMII_SPEED in the
assigned-clocks property of the gmac1 node. This result in a ENOENT
error when driver core tries to set a parent for this clock.

The clock speed in rgmii/rmii mode is changed using clk_set_rate of the
tx_rx clock and not using clk_set_parent of the speed clock.

Add dummy support for SCLK_GMAC1_RGMII_SPEED and similar clocks to clk
driver to allow a driver for gmac node to probe.

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 dabc7e7..599b7b1 100644
--- a/drivers/clk/rockchip/clk_rk3568.c
+++ b/drivers/clk/rockchip/clk_rk3568.c
@@ -2843,6 +2843,10 @@
 	case CLK_RKVDEC_CORE:
 		return rk3568_rkvdec_set_parent(clk, parent);
 	case I2S1_MCLKOUT_TX:
+	case SCLK_GMAC0_RGMII_SPEED:
+	case SCLK_GMAC0_RMII_SPEED:
+	case SCLK_GMAC1_RGMII_SPEED:
+	case SCLK_GMAC1_RMII_SPEED:
 		break;
 	default:
 		return -ENOENT;