rockchip: clk: rk3399: allow requests for HDMI clocks

This allows requests (via the DTS) for PCLK_HDMI_CTRL/PCLK_VIO_GRF,
which are clock gates in the HDMI output path for the RK3399.

As these are enabled by default (i.e. after reset), we don't implement
any logic to actively open/close these clock gates and simply assume
that their reset-default has not been changed.

Signed-off-by: Philipp Tomsich <philipp.tomsich@theobroma-systems.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/drivers/clk/rockchip/clk_rk3399.c b/drivers/clk/rockchip/clk_rk3399.c
index 10db46e..026ed4d 100644
--- a/drivers/clk/rockchip/clk_rk3399.c
+++ b/drivers/clk/rockchip/clk_rk3399.c
@@ -882,6 +882,9 @@
 	case SCLK_UART0:
 	case SCLK_UART2:
 		return 24000000;
+		break;
+	case PCLK_HDMI_CTRL:
+		break;
 	case DCLK_VOP0:
 	case DCLK_VOP1:
 		break;
@@ -922,6 +925,10 @@
 	case SCLK_SPI0...SCLK_SPI5:
 		ret = rk3399_spi_set_clk(priv->cru, clk->id, rate);
 		break;
+	case PCLK_HDMI_CTRL:
+	case PCLK_VIO_GRF:
+		/* the PCLK gates for video are enabled by default */
+		break;
 	case DCLK_VOP0:
 	case DCLK_VOP1:
 		ret = rk3399_vop_set_clk(priv->cru, clk->id, rate);