Input: ti_am335x_tsc - fix incorrect step config for 5 wire touchscreen

Step config setting for 5 wire touchscreen is incorrect for Y coordinates.
It was broken while we moved to DT. If you look close at the offending
commit bb76dc09ddfc ("input: ti_am33x_tsc: Order of TSC wires, made
configurable"), the change was:

- STEPCONFIG_XNP | STEPCONFIG_YPN;
+ ts_dev->bit_xn | ts_dev->bit_yp;

while bit_xn = STEPCONFIG_XNN and bit_yp = STEPCONFIG_YNN. Not quite the
same.

Fixes: bb76dc09ddfc ("input: ti_am33x_tsc: Order of TSC wires, made configurable")
Signed-off-by: Jeff Lance <[e-mail]>
[[e-mail]: Rebase to v4.14-rc1]
Signed-off-by: Vignesh R <[e-mail]>
Reviewed-by: Michael Nazzareno Trimarchi <[e-mail]>
Signed-off-by: Dmitry Torokhov <[e-mail]>

drivers/input/touchscreen/ti_am335x_tsc.c

···
 		break;
 	case 5:
 		config |= ts_dev->bit_xp | STEPCONFIG_INP_AN4 |
-				ts_dev->bit_xn | ts_dev->bit_yp;
+				STEPCONFIG_XNP | STEPCONFIG_YPN;
 		break;
 	case 8:
 		config |= ts_dev->bit_yp | STEPCONFIG_INP(ts_dev->inp_xp);