platform/x86: wmi: introduce helper to generate method names

Instead of "manually" constructing the ACPI method name and
hard-coding sizes in WMI functions, introduce a helper method
which generates the method name for an arbitrary WMI block.

Furthermore, save the appropriate buffer size into a macro.

Signed-off-by: Barnabás Pőcze <pobrn@protonmail.com>
Link: https://lore.kernel.org/r/20210904175450.156801-28-pobrn@protonmail.com


Reviewed-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>