Input: ti_am335x_tsc - clamp coordinate_readouts to DT maximum (6)

DT binding (ti,am3359-tsc.yaml) sets ti,coordinate-readouts to a
maximum of 6. The MFD parent also enforces that
(readouts * 2 + 2) + adc_channels <= 16 and fails probe if this
is violated, so the touchscreen subdriver will not even probe
in those cases.

Clamp coordinate_readouts > 6 to 6 in the subdriver to align with the
binding and keep behavior sane if invalid platform data bypasses schema
checks. Keep the existing default to 5 for non-positive values.

No functional change with valid DT.

Signed-off-by: Junjie Cao <junjie.cao@intel.com>
Link: https://patch.msgid.link/20251117032358.891822-1-junjie.cao@intel.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

Author: Junjie650

drivers/input/touchscreen/ti_am335x_tsc.c

@@ -389,6 +389,10 @@ static int titsc_parse_dt(struct platform_device *pdev,
 		dev_warn(&pdev->dev,
 			 "invalid co-ordinate readouts, resetting it to 5\n");
 		ts_dev->coordinate_readouts = 5;
+	} else if (ts_dev->coordinate_readouts > 6) {
+		dev_warn(&pdev->dev,
+			 "co-ordinate readouts too large, limiting to 6\n");
+		ts_dev->coordinate_readouts = 6;
 	}
 
 	err = of_property_read_u32(node, "ti,charge-delay",