drm/udl: Make udl driver depend on CONFIG_USB

The udl driver for DisplayLink devices depends on support for host-side
USB controllers, which is enabled with CONFIG_USB. Plain USB support as
given by CONFIG_USB_SUPPORT is not sufficient.

This patch changes dependencies for udl to depend on CONFIG_USB, instead
of CONFIG_USB_SUPPORT. Users will have to enable CONFIG_USB and select a
USB host controller. With this change udl dependencies work the same way
as dependencies for PCI drivers.

Signed-off-by: Thomas Zimmermann <[e-mail]>
Acked-by: Alex Deucher <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/udl/Kconfig

···
 config DRM_UDL
 	tristate "DisplayLink"
 	depends on DRM
-	depends on USB_SUPPORT
+	depends on USB
 	depends on USB_ARCH_HAS_HCD
-	select USB
 	select DRM_GEM_SHMEM_HELPER
 	select DRM_KMS_HELPER
 	help