tools: Pass the target in descend

 Fixing:

  [acme@sandy linux]$ cd tools
  [acme@sandy tools]$ make clean
      DESCEND power/cpupower
    CC       lib/cpufreq.o
    CC       lib/sysfs.o
    LD       libcpupower.so.0.0.0
    CC       utils/helpers/amd.o
  utils/helpers/amd.c:7:21: error: pci/pci.h: No such file or directory
  In file included from utils/helpers/amd.c:9:
  ./utils/helpers/helpers.h:137: warning: ‘struct pci_access’ declared inside parameter list
  ./utils/helpers/helpers.h:137: warning: its scope is only this definition or declaration, which is probably not what you want
  ./utils/helpers/helpers.h:139: warning: ‘struct pci_access’ declared inside parameter list
  utils/helpers/amd.c: In function ‘amd_pci_get_num_boost_states’:
  utils/helpers/amd.c:120: warning: passing argument 1 of ‘pci_slot_func_init’ from incompatible pointer type
  ./utils/helpers/helpers.h:138: note: expected ‘struct pci_access **’ but argument is of type ‘struct pci_access **’
  utils/helpers/amd.c:125: warning: implicit declaration of function ‘pci_read_byte’
  utils/helpers/amd.c:132: warning: implicit declaration of function ‘pci_cleanup’
  make[1]: *** [utils/helpers/amd.o] Error 1
  make: *** [cpupower_clean] Error 2
  [acme@sandy tools]$

Reported-by: Arnaldo Carvalho de Melo <acme@ghostprotocols.net>
Signed-off-by: David Howells <dhowells@redhat.com>
Cc: Borislav Petkov <bp@amd64.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Namhyung Kim <namhyung@gmail.com>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Link: http://lkml.kernel.org/n/tip-tviyimq6x6nm77sj5lt4t19f@git.kernel.org


Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>