clk: imx8mp: add mu root clk

Add mu root clk for mu mailbox usage.
Reviewed-by: Dong Aisheng <aisheng.dong@nxp.com>
Signed-off-by: Peng Fan <peng.fan@nxp.com>
Acked-by: Stephen Boyd <sboyd@kernel.org>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/clk/imx/clk-imx8mp.c

@@ -680,6 +680,7 @@ static int imx8mp_clocks_probe(struct platform_device *pdev)
 	hws[IMX8MP_CLK_I2C2_ROOT] = imx_clk_hw_gate4("i2c2_root_clk", "i2c2", ccm_base + 0x4180, 0);
 	hws[IMX8MP_CLK_I2C3_ROOT] = imx_clk_hw_gate4("i2c3_root_clk", "i2c3", ccm_base + 0x4190, 0);
 	hws[IMX8MP_CLK_I2C4_ROOT] = imx_clk_hw_gate4("i2c4_root_clk", "i2c4", ccm_base + 0x41a0, 0);
+	hws[IMX8MP_CLK_MU_ROOT] = imx_clk_hw_gate4("mu_root_clk", "ipg_root", ccm_base + 0x4210, 0);
 	hws[IMX8MP_CLK_OCOTP_ROOT] = imx_clk_hw_gate4("ocotp_root_clk", "ipg_root", ccm_base + 0x4220, 0);
 	hws[IMX8MP_CLK_PCIE_ROOT] = imx_clk_hw_gate4("pcie_root_clk", "pcie_aux", ccm_base + 0x4250, 0);
 	hws[IMX8MP_CLK_PWM1_ROOT] = imx_clk_hw_gate4("pwm1_root_clk", "pwm1", ccm_base + 0x4280, 0);