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

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.fr
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>