clk: rockchip: rk3399: Add dummy support for ACLK_VDU clock

rk3399.dtsi from linux v5.19 and newer try to set VDU clock rate to
400 MHz using an assigned-clock-rates prop of the CRU node.

U-Boot does not use or need this clock so add dummy support for getting
and setting ACLK_VDU clock rate to allow CRU driver to be loaded with an
updated rk3399.dtsi.

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

drivers/clk/rockchip/clk_rk3399.c

@@ -971,6 +971,7 @@ static ulong rk3399_clk_get_rate(struct clk *clk)
 	case ACLK_HDCP:
 	case ACLK_GIC_PRE:
 	case PCLK_DDR:
+	case ACLK_VDU:
 		break;
 	case PCLK_ALIVE:
 	case PCLK_WDT:
@@ -1061,6 +1062,7 @@ static ulong rk3399_clk_set_rate(struct clk *clk, ulong rate)
 	case ACLK_HDCP:
 	case ACLK_GIC_PRE:
 	case PCLK_DDR:
+	case ACLK_VDU:
 		return 0;
 	default:
 		log_debug("Unknown clock %lu\n", clk->id);