clk: imx7d: add IMX7D_MU_ROOT_CLK

This clock is needed for iMX mailbox driver

Signed-off-by: Oleksij Rempel <o.rempel@pengutronix.de>
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Reviewed-by: Fabio Estevam <fabio.estevam@nxp.com>
Signed-off-by: Stephen Boyd <sboyd@kernel.org>
diff --git a/drivers/clk/imx/clk-imx7d.c b/drivers/clk/imx/clk-imx7d.c
index 27217a7e..881b772 100644
--- a/drivers/clk/imx/clk-imx7d.c
+++ b/drivers/clk/imx/clk-imx7d.c
@@ -797,6 +797,7 @@
 	clks[IMX7D_DRAM_ALT_ROOT_CLK] = imx_clk_gate4("dram_alt_root_clk", "dram_alt_post_div", base + 0x4130, 0);
 	clks[IMX7D_OCOTP_CLK] = imx_clk_gate4("ocotp_clk", "ipg_root_clk", base + 0x4230, 0);
 	clks[IMX7D_SNVS_CLK] = imx_clk_gate4("snvs_clk", "ipg_root_clk", base + 0x4250, 0);
+	clks[IMX7D_MU_ROOT_CLK] = imx_clk_gate4("mu_root_clk", "ipg_root_clk", base + 0x4270, 0);
 	clks[IMX7D_CAAM_CLK] = imx_clk_gate4("caam_clk", "ipg_root_clk", base + 0x4240, 0);
 	clks[IMX7D_USB_HSIC_ROOT_CLK] = imx_clk_gate4("usb_hsic_root_clk", "usb_hsic_post_div", base + 0x4690, 0);
 	clks[IMX7D_SDMA_CORE_CLK] = imx_clk_gate4("sdma_root_clk", "ahb_root_clk", base + 0x4480, 0);