It is used in the build process, so stop suppressing its build in tools
cross builds.

Signed-off-by: Jiri Olsa
Tested-by: Arnaldo Carvalho de Melo
Cc: Andi Kleen
Cc: Madhavan Srinivasan
Cc: Peter Zijlstra
Cc: Sukadev Bhattiprolu
Cc: linuxppc-dev@lists.ozlabs.org
Link: http://lkml.kernel.org/r/20160927141846.GA6589@krava
[ Use HOSTCC on the $(OUTPUT)fixdep target, it was using the x-compiler
to link fixdep-in.o, that was correctly built with HOSTCC and thus failing ]
Signed-off-by: Arnaldo Carvalho de Melo