Input: imagis - fix warning regarding 'imagis_3038_data' being unused

Input: imagis - fix warning regarding 'imagis_3038_data' being unused

Fix the following compilation warnings:
drivers/input/touchscreen/imagis.c:422:39: warning: ‘imagis_3038c_data’
defined but not used [-Wunused-const-variable=]
  422 | static const struct imagis_properties imagis_3038c_data = {
drivers/input/touchscreen/imagis.c:415:39: warning: ‘imagis_3038b_data’
defined but not used [-Wunused-const-variable=]
  415 | static const struct imagis_properties imagis_3038b_data = {
drivers/input/touchscreen/imagis.c:407:39: warning: ‘imagis_3038_data’
defined but not used [-Wunused-const-variable=]
  407 | static const struct imagis_properties imagis_3038_data = {
drivers/input/touchscreen/imagis.c:398:39: warning: ‘imagis_3032c_data’
defined but not used [-Wunused-const-variable=]
  398 | static const struct imagis_properties imagis_3032c_data = {

Only define the variables 'imagis_303*_data' when the CONFIG_OF
is enabled.

Fixes: 1e48ee99f603 ("Input: imagis - add supports for Imagis IST3038")
Signed-off-by: Zeng Heng <zengheng4@huawei.com>
Acked-by: Markuss Broks <markuss.broks@gmail.com>
Link: https://lore.kernel.org/r/20241023094831.1680214-1-zengheng4@huawei.com
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>