ARM: imx6: Initialize low-power mode early again

Since commit 9e8147bb5e
"ARM: imx6q: move low-power code out of clock driver"
the kernel fails to boot on i.MX6Q/D if preemption is
enabled (CONFIG_PREEMPT=y). The kernel just hangs
before the console comes up.

The above commit moved the initalization of the low-power
mode setting (enabling clocked WAIT states), which was
introduced in commit 83ae20981a
"ARM: imx: correct low-power mode setting", from
imx6q_clks_init to imx6q_pm_init. Now it is called
much later, after all cores are enabled.

This patch moves the low-power mode initialization back
to imx6q_clks_init again (and to imx6sl_clks_init).

Signed-off-by: Philipp Zabel <p.zabel@pengutronix.de>
Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
Signed-off-by: Kevin Hilman <khilman@linaro.org>

arch/arm/mach-imx/clk-imx6q.c

@@ -482,6 +482,9 @@ static void __init imx6q_clocks_init(struct device_node *ccm_node)
 	if (IS_ENABLED(CONFIG_PCI_IMX6))
 		clk_set_parent(clk[lvds1_sel], clk[sata_ref]);
 
+	/* Set initial power mode */
+	imx6q_set_lpm(WAIT_CLOCKED);
+
 	np = of_find_compatible_node(NULL, NULL, "fsl,imx6q-gpt");
 	base = of_iomap(np, 0);
 	WARN_ON(!base);

arch/arm/mach-imx/clk-imx6sl.c

@@ -266,6 +266,9 @@ static void __init imx6sl_clocks_init(struct device_node *ccm_node)
 	/* Audio-related clocks configuration */
 	clk_set_parent(clks[IMX6SL_CLK_SPDIF0_SEL], clks[IMX6SL_CLK_PLL3_PFD3]);
 
+	/* Set initial power mode */
+	imx6q_set_lpm(WAIT_CLOCKED);
+
 	np = of_find_compatible_node(NULL, NULL, "fsl,imx6sl-gpt");
 	base = of_iomap(np, 0);
 	WARN_ON(!base);

arch/arm/mach-imx/pm-imx6q.c

@@ -236,8 +236,6 @@ void __init imx6q_pm_init(void)
 		regmap_update_bits(gpr, IOMUXC_GPR1, IMX6Q_GPR1_GINT,
 				   IMX6Q_GPR1_GINT);
 
-	/* Set initial power mode */
-	imx6q_set_lpm(WAIT_CLOCKED);
 
 	suspend_set_ops(&imx6q_pm_ops);
 }