platform/x86: int3472: discrete: Add alternative "AVDD" regulator supply name

Add an "AVDD" regulator supply name alias to the supply-map which
gets registered for the INT3472 GPIO regulator.

This is necessary for the ov2680 driver which expects "AVDD" rather then
"avdd". Updating the ov2680 driver to use "avdd" is not possible because
that will break compatibility with existing DT / DTB files.

Tested-by: Hao Yao <hao.yao@intel.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Daniel Scally <dan.scally@ideasonboard.com>
Link: https://lore.kernel.org/r/20230616172132.37859-5-hdegoede@redhat.com