pinctrl: sx150x: handle missing 'advanced' reg in sx1504 and sx1505

This fixes a problem where sx150x_regmap_reg_width() returns 8 for the
data register (reg 0) for sx1504 where it should return 4, and return
a correct 8 for sx1505 but for the wrong reason (both chips lack the
'advanced' register). This is not a real problem, since nothing depends
on the function returning 4 or 8, and certainly not if it is returning
8 for the wrong reason. But fix this to avoid nasty surprises down the
line.
Signed-off-by: Peter Rosin <peda@axentia.se>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>

drivers/pinctrl/pinctrl-sx150x.c

@@ -967,6 +967,7 @@ static int sx150x_regmap_reg_width(struct sx150x_pinctrl *pctl,
 		    reg == data->pri.x123.reg_advanced)
 		   ||
 		   (data->model == SX150X_456 &&
+		    data->pri.x456.reg_advanced &&
 		    reg == data->pri.x456.reg_advanced)) {
 		return 8;
 	} else {