ide: move legacy ISA/VLB ports handling to ide-legacy.c (v2)

* Move legacy ISA/VLB ports handling from ide-probe.c to ide-legacy.c.

* Add CONFIG_IDE_LEGACY config option to be selected by host drivers
  needing ide-legacy.c.

v2:
Fix CONFIG_IDE_LEGACY not being defined in Kconfig.
(from Takashi Iwai <tiwai@suse.de>)

There should be no functional changes caused by this patch.

Signed-off-by: Bartlomiej Zolnierkiewicz <bzolnier@gmail.com>
diff --git a/drivers/ide/Makefile b/drivers/ide/Makefile
index bdc7b81..177e3f8 100644
--- a/drivers/ide/Makefile
+++ b/drivers/ide/Makefile
@@ -15,6 +15,7 @@
 ide-core-$(CONFIG_BLK_DEV_IDEDMA_SFF)	+= ide-dma-sff.o
 ide-core-$(CONFIG_IDE_PROC_FS)		+= ide-proc.o
 ide-core-$(CONFIG_BLK_DEV_IDEACPI)	+= ide-acpi.o
+ide-core-$(CONFIG_IDE_LEGACY)		+= ide-legacy.o
 
 obj-$(CONFIG_IDE)			+= ide-core.o