platform/x86: int3472: Rename pled to led in LED registration code

platform/x86: int3472: Rename pled to led in LED registration code

Rename the privacy LED type, struct member, and functions from "pled"
to "led" in preparation for supporting additional LED types beyond
just the privacy LED.

No functional change.

Reviewed-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Reviewed-by: Hans de Goede <johannes.goede@oss.qualcomm.com>
Signed-off-by: Marco Nenciarini <mnencia@kcore.it>
Link: https://patch.msgid.link/20260401203638.1601661-3-mnencia@kcore.it
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>