package/wilc-driver: add missing BR2_LINUX_KERNEL dependency

Fixes:
 - http://autobuild.buildroot.net/results/40b/40b8aa0c19917f64c3f272f5479068e7631ffcc3

Signed-off-by: James Hilliard <james.hilliard1@gmail.com>
Reviewed-by: Kris Bahnsen <kris@embeddedTS.com>
Signed-off-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>

package/wilc-driver/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_WILC_DRIVER
 	bool "wilc kernel module"
+	depends on BR2_LINUX_KERNEL
 	help
 	  External kernel module for WILC1000/3000 devices.
 
@@ -16,6 +17,9 @@ config BR2_PACKAGE_WILC_DRIVER
 
 	  https://github.com/embeddedTS/wilc3000-external-module
 
+comment "wilc kernel module needs a Linux kernel to be built"
+	depends on !BR2_LINUX_KERNEL
+
 if BR2_PACKAGE_WILC_DRIVER
 
 config BR2_PACKAGE_WILC_DRIVER_SPI