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: NMathias Krause <minipli@googlemail.com>
Cc: "Lee, Chun-Yi" <jlee@suse.com>
Signed-off-by: NMatthew Garrett <matthew.garrett@nebula.com>