package/udev: convert to the virtual-package infrastructure

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Eric Le Bihan <eric.le.bihan.dev@free.fr>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Thomas De Schampheleire <patrickdepinguin@gmail.com>
Cc: Mike Zick <minimod@morethan.org>
[eric.le.bihan.dev@free.fr: tested with both systemd and eudev, on QEMU x86]
Tested-by: Eric Le Bihan <eric.le.bihan.dev@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/udev/udev.mk

@@ -4,13 +4,4 @@
 #
 ################################################################################
 
-UDEV_SOURCE =
-UDEV_DEPENDENCIES = $(call qstrip,$(BR2_PACKAGE_PROVIDES_UDEV))
-
-ifeq ($(BR2_PACKAGE_HAS_UDEV),y)
-ifeq ($(UDEV_DEPENDENCIES),)
-$(error No Udev implementation selected. Configuration error)
-endif
-endif
-
-$(eval $(generic-package))
+$(eval $(virtual-package))