automake: Fix Linux build with --disable-apm --disable-acpi

Fixes: accd32a4 (xorg: Remove the XF86PM define.)
Signed-off-by: Adam Jackson <ajax@redhat.com>
1 job for autotools-no-pm in 5 minutes and 34 seconds
Status Job ID Name Coverage
  Test
passed #25683
job

00:05:34