drivers/bcma/host_pci.c needs slab.h

alpha allmodconfig:

  drivers/bcma/host_pci.c: In function 'bcma_host_pci_probe':
  drivers/bcma/host_pci.c:102: error: implicit declaration of function 'kzalloc'
  drivers/bcma/host_pci.c:102: warning: assignment makes pointer from integer without a cast

Cc: <zajec5@gmail.com>
Cc: John W. Linville <linville@tuxdriver.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>