Input: imx_keypad - only set enabled columns to open-drain

In imx_keypad_inhibit(), all 8 columns were set to open-drain, in
contrast to the rest of the driver, where only the enabled columns
are modified/used.

Contrary to the normal expectation, this also affects column I/Os not
even mapped via IOMUX to the KPP hardware module but used as a GPIO.
Therefore only init enabled columns to open-drain and leave all others
with their default reset value of 0, i.e. totem-pole.
Signed-off-by: Andreas Pretzsch <apr@cn-eng.de>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>

drivers/input/keyboard/imx_keypad.c

@@ -362,7 +362,8 @@ static void imx_keypad_inhibit(struct imx_keypad *keypad)
 	writew(reg_val, keypad->mmio_base + KPSR);
 
 	/* Colums as open drain and disable all rows */
-	writew(0xff00, keypad->mmio_base + KPCR);
+	reg_val = (keypad->cols_en_mask & 0xff) << 8;
+	writew(reg_val, keypad->mmio_base + KPCR);
 }
 
 static void imx_keypad_close(struct input_dev *dev)