staging: ti-st: fix kim platform device id

Platform devices tend to have id as -1 when only 1 device exist and
a value >=0 when multiple devices exist, since we plan to store all
these platform devices if multiple exist, there was a requirement to
have id to be >=0.
The patch fixes this problem.
Signed-off-by: Pavan Savoy <pavan_savoy@ti.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>

drivers/staging/ti-st/st_kim.c

@@ -638,7 +638,14 @@ static int kim_probe(struct platform_device *pdev)
 	long *gpios = pdev->dev.platform_data;
 	struct kim_data_s	*kim_gdata;
 
-	st_kim_devices[pdev->id] = pdev;
+	if ((pdev->id != -1) && (pdev->id < MAX_ST_DEVICES)) {
+		/* multiple devices could exist */
+		st_kim_devices[pdev->id] = pdev;
+	} else {
+		/* platform's sure about existance of 1 device */
+		st_kim_devices[0] = pdev;
+	}
+
 	kim_gdata = kzalloc(sizeof(struct kim_data_s), GFP_ATOMIC);
 	if (!kim_gdata) {
 		pr_err("no mem to allocate");