Remove dl-procinfo.h

powerpc was the only architecture with arch-specific hooks for
LD_SHOW_AUXV, and with the information moved to ld diagnostics there
is no need to keep the _dl_procinfo hook.

Checked with a build for all affected ABIs.

Reviewed-by: Peter Bergner <bergner@linux.ibm.com>

scripts/gen-tunables.awk

@@ -141,7 +141,6 @@ END {
   print "# error \"Do not include this file directly.\""
   print "# error \"Include tunables.h instead.\""
   print "#endif"
-  print "#include <dl-procinfo.h>\n"
 
   # Now, the enum names
   print "\ntypedef enum"