udev: ensure /dev mgmt option is in sync

These options should be in sync, both for consistency and because udev
needs devtmpfs enabled in the kernel.

We unfortunately cannot just select BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_UDEV
here, as that one selects udev - leading to recursion erors, so instead
we use depends on.

Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/udev/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_UDEV
 	bool "udev"
+	depends on BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_UDEV
 	help
 	  Userspace device daemon.
 
@@ -25,3 +26,6 @@ comment "udev extras requires a toolchain with LARGEFILE + WCHAR support"
 	depends on !(BR2_LARGEFILE && BR2_USE_WCHAR)
 
 endif
+
+comment "udev requires /dev mgmnt set to udev under System configuration"
+	depends on !BR2_ROOTFS_DEVICE_CREATION_DYNAMIC_UDEV