Fix the following compile error with CONFIG_ATA=y, CONFIG_BLOCK=n:

...
  CC      drivers/ata/libata-scsi.o
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c: In function ‘ata_scsi_dev_config’:
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:791: warning: implicit declaration of function ‘blk_queue_max_sectors’
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:799: error: ‘request_queue_t’ undeclared (first use in this function)
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:799: error: (Each undeclared identifier is reported only once
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:799: error: for each function it appears in.)
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:799: error: ‘q’ undeclared (first use in this function)
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:800: warning: implicit declaration of function ‘blk_queue_max_hw_segments’
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c: In function ‘ata_scsi_slave_config’:
/home/bunk/linux/kernel-2.6/git/linux-2.6/drivers/ata/libata-scsi.c:831:
warning: implicit declaration of function ‘blk_queue_max_phys_segments’
make[3]: *** [drivers/ata/libata-scsi.o] Error 1

Bug report by Jesper Juhl.
Signed-off-by: Adrian Bunk <bunk@stusta.de>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Jeff Garzik <jeff@garzik.org>