gpio: Handle stmpe-gpio platform data with no gpio base

This patch removes the requirement that gpio base be supplied in
platform data.

Signed-off-by: Virupax Sadashivpetimath <[e-mail]>
Acked-by: Linus Walleij <[e-mail]>
Acked-by: Wolfram Sang <[e-mail]>
Signed-off-by: Samuel Ortiz <[e-mail]>

drivers/gpio/stmpe-gpio.c

···
 	int irq;
 
 	pdata = stmpe->pdata->gpio;
-	if (!pdata)
-		return -ENODEV;
 
 	irq = platform_get_irq(pdev, 0);
 	if (irq < 0)