platform/x86: asus-wmi: store a min default for ppt options

platform/x86: asus-wmi: store a min default for ppt options

Laptops with any of the ppt or nv tunables default to the minimum setting
on boot so we can safely assume a stored value is correct.

This patch adds storing of those values in the local struct, and enables
reading of those values back. To prevent creating a series of byte holes
in the struct the "<name>_available" bool is removed and
`asus_sysfs_is_visible()` uses the `ASUS_WMI_DEVID_<name>` directly.

Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Luke D. Jones <luke@ljones.dev>
Link: https://lore.kernel.org/r/20240404001652.86207-6-luke@ljones.dev
Signed-off-by: Hans de Goede <hdegoede@redhat.com>