acer-wmi: Mark init data and code as such

acer-wmi: Mark init data and code as such

Quite a lot of code and data of acer-wmi.c is only ever used during
initialization. Mark those accordingly -- and constify, where
appropriate -- so the memory can be released afterwards.

All in all those changes move ~10 kB of code and data to the .init
sections, marking them for release after initialization has finished.

Signed-off-by: Mathias Krause <[email protected]>
Cc: "Lee, Chun-Yi" <[email protected]>
Signed-off-by: Matthew Garrett <[email protected]>