x86/apm_32: Remove dead function apm_get_battery_status()

This part was commented out 25 years ago in:

  commit d43c43b46ebfdb437b78206fcc1992c4d2e8c15e
  Author: linus1 <torvalds@linuxfoundation.org>
  Date:   Tue Sep 7 11:00:00 1999 -0600

      Import 2.3.26pre1

and probably no one knows why. Probably it was unused even then.

Just remove it.

  [ bp: Expand commit message. ]

Signed-off-by: Kunwu Chan <chentao@kylinos.cn>
Signed-off-by: Borislav Petkov (AMD) <bp@alien8.de>
Link: https://lore.kernel.org/r/20240126030824.579711-1-chentao@kylinos.cn