There are systems that use ATRM, but not ATPX.

Fixes:
https://bugs.freedesktop.org/show_bug.cgi?id=41265

V2: fix #ifdefs as per Greg's comments
V3: fix it harder
Signed-off-by: NAlex Deucher <alexander.deucher@amd.com>
Cc: stable@vger.kernel.org