iio: light: gp2ap020a00f: Remove some unused field in struct gp2ap020a00f_data

In "struct gp2ap020a00f_data", the 'pdata' field is unused.

Moreover the "struct gp2ap020a00f_platform_data" is defined nowhere.
Neither in this file, nor in a global .h file, so it is completely
pointless.

So, remove it.

Found with cppcheck, unusedStructMember.
Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Link: https://lore.kernel.org/r/57e9f29c7062d1bb846064bf6dbd7a8385a855e7.1714568099.git.christophe.jaillet@wanadoo.frSigned-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>

drivers/iio/light/gp2ap020a00f.c

@@ -237,7 +237,6 @@ enum gp2ap020a00f_thresh_val_id {
 };
 
 struct gp2ap020a00f_data {
-	const struct gp2ap020a00f_platform_data *pdata;
 	struct i2c_client *client;
 	struct mutex lock;
 	char *buffer;