已解决! 转到解答。
I clone the code from link:https://source.codeaurora.org/external/imx/linux-imx
and checkout to the branch: imx_5.4.70_2.3.0
the code is in `imx_hdmimix_clk_probe` function of the file `drivers/clk/imx/clk-hdmimix.c`.
clks[IMX8MP_CLK_HDMIMIX_FDCC_REF_CLK] = imx_dev_clk_gate(dev, "hdmi_fdcc_ref", "hdmi_fdcc_tst", base + 0x50, 2);
clks[IMX8MP_CLK_HDMIMIX_HRV_MWR_APB_CLK] = imx_dev_clk_gate(dev, "hrv_mwr_apb", "hdmi_glb_apb", base + 0x50, 3);