iio: frequency: ad9523: fix multi-line dereferences

iio: frequency: ad9523: fix multi-line dereferences

Platform data pointer dereferences for pll1_charge_pump_current_nA and
pll2_charge_pump_current_nA were split across multiple lines. Bring the
dereference chains onto a single line.

This resolves the following checkpatch.pl warnings:
WARNING: Avoid multiple line dereference - prefer 'pdata->pll1_charge_pump_current_nA'
WARNING: Avoid multiple line dereference - prefer 'pdata->pll2_charge_pump_current_nA'

Signed-off-by: Bhargav Joshi <rougueprince47@gmail.com>
Reviewed-by: Andy Shevchenko <andriy.shevchenko@intel.com>
Signed-off-by: Jonathan Cameron <Jonathan.Cameron@huawei.com>