clk: rockchip: rk3568: Add dummy I2S1_MCLKOUT_TX clock support

A RK3568 device tree pmic node can reference the I2S1_MCLKOUT_TX clock
in assigned-clocks, add dummy support to set parent of this clock to the
rk3568 cru driver.

Fixes probe of pmic driver and missing regulators on affected boards,
rk3568-evb and rk3568-rock-3a.

Signed-off-by: Jonas Karlman <jonas@kwiboo.se>
Reviewed-by: Kever Yang <kever.yang@rock-chips.com>

drivers/clk/rockchip/clk_rk3568.c

@@ -2838,6 +2838,8 @@ static int rk3568_clk_set_parent(struct clk *clk, struct clk *parent)
 	case ACLK_RKVDEC_PRE:
 	case CLK_RKVDEC_CORE:
 		return rk3568_rkvdec_set_parent(clk, parent);
+	case I2S1_MCLKOUT_TX:
+		break;
 	default:
 		return -ENOENT;
 	}