package/udev: fix dependency for scsi_id

According to udev.mk, the scsi_id package depends on the libvolume_id
library, so add this dependency to Config.mk

Signed-off-by: Jeremy Kerr <jk@ozlabs.org>

package/udev/Config.in

@@ -23,7 +23,7 @@ config BR2_PACKAGE_UDEV_VOLUME_ID
 
 config BR2_PACKAGE_UDEV_SCSI_ID
 	bool "udev-scsi_id"
-	depends on BR2_PACKAGE_UDEV
+	depends on BR2_PACKAGE_UDEV_VOLUME_ID
 	help
 	  Build and install SCSI disk identification library.