platform/x86: asus-wmi: export symbols used for read/write WMI

platform/x86: asus-wmi: export symbols used for read/write WMI

Export symbols for reading/writing WMI symbols using a namespace.
Existing functions:
- asus_wmi_evaluate_method
- asus_wmi_set_devstate
New function:
- asus_wmi_get_devstate_dsts

The new function is intended for use with DSTS WMI method only and
avoids requiring the asus_wmi driver data to select the WMI method.

Co-developed-by: Denis Benato <denis.benato@linux.dev>
Signed-off-by: Denis Benato <denis.benato@linux.dev>
Signed-off-by: Luke D. Jones <luke@ljones.dev>
Reviewed-by: Mario Limonciello <mario.limonciello@amd.com>
Link: https://patch.msgid.link/20251102215319.3126879-2-denis.benato@linux.dev
Reviewed-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>
Signed-off-by: Ilpo Järvinen <ilpo.jarvinen@linux.intel.com>