gpio: zevio: Add missing header

The commit 899f6a9 ("gpio: zevio: Use proper headers and drop
OF_GPIO dependency") missed one header this driver depends on. Add it.

Fixes: 899f6a9 ("gpio: zevio: Use proper headers and drop OF_GPIO dependency")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Signed-off-by: Bartosz Golaszewski <bartosz.golaszewski@linaro.org>

drivers/gpio/gpio-zevio.c

@@ -10,6 +10,7 @@
 #include <linux/init.h>
 #include <linux/io.h>
 #include <linux/mod_devicetable.h>
+#include <linux/platform_device.h>
 #include <linux/slab.h>
 #include <linux/spinlock.h>