Always build hweight8/16/32/64() functions into the kernel so that loadable
modules may use them.

I didn't remove GENERIC_HWEIGHT since ALPHA_EV67, ia64, and some variants
of UltraSparc(64) provide their own hweight functions.

Fixes config/build problems with NTFS=m and JOYSTICK_ANALOG=m.

  Kernel: arch/x86_64/boot/bzImage is ready  (#19)
    Building modules, stage 2.
    MODPOST 94 modules
  WARNING: "hweight32" [fs/ntfs/ntfs.ko] undefined!
  WARNING: "hweight16" [drivers/input/joystick/analog.ko] undefined!
  WARNING: "hweight8" [drivers/input/joystick/analog.ko] undefined!
  make[1]: *** [__modpost] Error 1
  make: *** [modules] Error 2
Signed-off-by: Randy Dunlap <randy.dunlap@oracle.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>