thermal: imx_tmu: Fix the polling default

When the 'polling-delay' property is not passed via devicetree,
pdata->polling_delay keeps at 0. This causes the imx_tmu driver to get
stuck inside the busy while() loop when the CPU temperature is above
the alert point.

Fix this problem by passing a one second polling interval, which provides
a proper delay to let the system to cool down and exit the while() loop
when the temperature is below the alert point.

Signed-off-by: Fabio Estevam <festevam@denx.de>
diff --git a/drivers/thermal/imx_tmu.c b/drivers/thermal/imx_tmu.c
index 97efc55..d9a04ea 100644
--- a/drivers/thermal/imx_tmu.c
+++ b/drivers/thermal/imx_tmu.c
@@ -37,6 +37,7 @@
 #define TER_ADC_PD		0x40000000
 #define TER_ALPF		0x3
 
+#define IMX_TMU_POLLING_DELAY_MS	1000
 /*
  * i.MX TMU Registers
  */
@@ -574,6 +575,8 @@
 
 	dev_dbg(dev, "%s\n", __func__);
 
+	pdata->polling_delay = IMX_TMU_POLLING_DELAY_MS;
+
 	if (pdata->zone_node) {
 		pdata->regs = (union tmu_regs *)dev_read_addr_ptr(dev);
 
@@ -602,7 +605,8 @@
 
 	dev_dbg(dev, "args.args_count %d, id %d\n", args.args_count, pdata->id);
 
-	pdata->polling_delay = dev_read_u32_default(dev, "polling-delay", 1000);
+	pdata->polling_delay = dev_read_u32_default(dev, "polling-delay",
+						    IMX_TMU_POLLING_DELAY_MS);
 
 	trips_np = ofnode_path("/thermal-zones/cpu-thermal/trips");
 	ofnode_for_each_subnode(trips_np, trips_np) {