clk: imx: Add a virtual arm clk on i.mx7d

Add a virtual arm clk to abstract the actual steps
when changing the ARM core frequency.So we can using
the 'cpufreq-dt' driver on i.MX7D/Solo.
Signed-off-by: Bai Ping <b51503@freescale.com>
Acked-by: Lucas Stach <l.stach@pengutronix.de>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>

drivers/clk/imx/clk-imx7d.c

@@ -833,6 +833,12 @@ static void __init imx7d_clocks_init(struct device_node *ccm_node)
 
 	clks[IMX7D_GPT_3M_CLK] = imx_clk_fixed_factor("gpt_3m", "osc", 1, 8);
 
+	clks[IMX7D_CLK_ARM] = imx_clk_cpu("arm", "arm_a7_root_clk",
+					 clks[IMX7D_ARM_A7_ROOT_CLK],
+					 clks[IMX7D_ARM_A7_ROOT_SRC],
+					 clks[IMX7D_PLL_ARM_MAIN_CLK],
+					 clks[IMX7D_PLL_SYS_MAIN_CLK]);
+
 	for (i = 0; i < ARRAY_SIZE(clks); i++)
 		if (IS_ERR(clks[i]))
 			pr_err("i.MX7D clk %d: register failed with %ld\n",

include/dt-bindings/clock/imx7d-clock.h

@@ -447,5 +447,6 @@
 #define IMX7D_SEMA4_HS_ROOT_CLK		434
 #define IMX7D_PLL_DRAM_TEST_DIV		435
 #define IMX7D_ADC_ROOT_CLK		436
-#define IMX7D_CLK_END			437
+#define IMX7D_CLK_ARM			437
+#define IMX7D_CLK_END			438
 #endif /* __DT_BINDINGS_CLOCK_IMX7D_H */