apm: orphan the driver

I no longer have access to any hardware that uses APM and have not
provided real maintenance for several years.  Hopefully someone with the
hardware or energy will step forward if the driver is to be kept.

Signed-off-by: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>