drivers: leds: leds-tca6507: check CONFIG_GPIOLIB whether defined for 'gpio_base'

Need check CONFIG_GPIOLIB whether defined, just like another area has
done within this file. Or can not pass compiling when CONFIG_GPIOLIB
disabled.

The related error (with allmodconfig for metag):

CC [M] drivers/leds/leds-tca6507.o
drivers/leds/leds-tca6507.c: In function 'tca6507_led_dt_init':
drivers/leds/leds-tca6507.c:731: error: 'struct tca6507_platform_data' has no member named 'gpio_base'

Signed-off-by: Chen Gang <[e-mail]>
Signed-off-by: Bryan Wu <[e-mail]>

drivers/leds/leds-tca6507.c

···
 
 	pdata->leds.leds = tca_leds;
 	pdata->leds.num_leds = NUM_LEDS;
+#ifdef CONFIG_GPIOLIB
 	pdata->gpio_base = -1;
-
+#endif
 	return pdata;
 }