ide: add IDE_HFLAG_BOOTABLE host flag

Add IDE_HFLAG_BOOTABLE host flag and IDE_HFLAG_OFF_BOARD define.  Convert
all host drivers using ide_pci_device_t to use IDE_HFLAG_{BOOTABLE,OFF_BOARD}
instead of d->bootable and then remove no longer needed d->bootable.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/pci/tc86c001.c b/drivers/ide/pci/tc86c001.c
index 0e3a8fe..6f2d536 100644
--- a/drivers/ide/pci/tc86c001.c
+++ b/drivers/ide/pci/tc86c001.c
@@ -228,8 +228,7 @@
 	.init_chipset	= init_chipset_tc86c001,
 	.init_hwif	= init_hwif_tc86c001,
 	.autodma	= AUTODMA,
-	.bootable	= OFF_BOARD,
-	.host_flags	= IDE_HFLAG_SINGLE,
+	.host_flags	= IDE_HFLAG_SINGLE | IDE_HFLAG_OFF_BOARD,
 	.pio_mask	= ATA_PIO4,
 };