Staging: unisys: virthba: Add dependency on SCSI

If CONFIG_SCSI is not enabled, compiling virthba.c goes horribly wrong with
undefined symbols.
Reported-by: kbuild test robot <fengguang.wu@intel.com>
Signed-off-by: Ken Cox <jkc@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/unisys/virthba/Kconfig

@@ -4,7 +4,7 @@
 
 config UNISYS_VIRTHBA
 	tristate "Unisys virthba driver"
-	depends on UNISYSSPAR && UNISYS_VISORCHIPSET && UNISYS_CHANNELSTUB && UNISYS_UISLIB && UNISYS_VIRTPCI
+	depends on UNISYSSPAR && UNISYS_VISORCHIPSET && UNISYS_CHANNELSTUB && UNISYS_UISLIB && UNISYS_VIRTPCI && SCSI
 	---help---
 	If you say Y here, you will enable the Unisys virthba driver.