Thermal: imx: add clk disable/enable for suspend/resume

Thermal sensor's clk is from pll3_usb_otg, per hardware
design requirement, need to make sure pll3_usb_otg is disabled
before STOP mode is entered, otherwise, all PFDs under it may
enter incorrect state, this patch disables pll3_usb_otg before
suspend and enables it after resume.

Signed-off-by: Anson Huang <b20788@freescale.com>
Signed-off-by: Eduardo Valentin <edubezval@gmail.com>
diff --git a/drivers/thermal/imx_thermal.c b/drivers/thermal/imx_thermal.c
index c1188ac..2ccbc07 100644
--- a/drivers/thermal/imx_thermal.c
+++ b/drivers/thermal/imx_thermal.c
@@ -608,6 +608,7 @@
 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_MEASURE_TEMP);
 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_POWER_DOWN);
 	data->mode = THERMAL_DEVICE_DISABLED;
+	clk_disable_unprepare(data->thermal_clk);
 
 	return 0;
 }
@@ -617,6 +618,7 @@
 	struct imx_thermal_data *data = dev_get_drvdata(dev);
 	struct regmap *map = data->tempmon;
 
+	clk_prepare_enable(data->thermal_clk);
 	/* Enabled thermal sensor after resume */
 	regmap_write(map, TEMPSENSE0 + REG_CLR, TEMPSENSE0_POWER_DOWN);
 	regmap_write(map, TEMPSENSE0 + REG_SET, TEMPSENSE0_MEASURE_TEMP);