procps: fix build with make 3.82

Based on patch by Bruce Bushby.

Issue with make include order. For more details, see:
http://old.nabble.com/make-3.81.91---procps-3.2.8-td29281048.html

Equivalent to upstream fix:
http://procps.cvs.sourceforge.net/viewvc/procps/procps/Makefile?r1=1.70&r2=1.71



Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>