linux-fusion: add dependency on !BR2_KERNEL_none

linux-fusion is composed of a kernel module, and linux-fusion.mk uses
several variable definitions that only exist when Buildroot compiles a
kernel.

We also add the same dependency to BR2_PACKAGE_DIRECTFB_MULTI, which
relies on linux-fusion.

Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>

package/directfb/Config.in

@@ -10,6 +10,7 @@ if BR2_PACKAGE_DIRECTFB
 config BR2_PACKAGE_DIRECTFB_MULTI
 	bool "directfb multi application"
 	select BR2_PACKAGE_LINUX_FUSION
+	depends on !BR2_KERNEL_none
 	help
 	  Enable use of multiple concurrent DirectFB applications
 

package/linux-fusion/Config.in

@@ -1,4 +1,5 @@
 config BR2_PACKAGE_LINUX_FUSION
+	depends on !BR2_KERNEL_none
 	bool "linux-fusion communication layer for DirectFB multi"
 	help
 	  DirectFB Communication Layer allowing multiple DirectFB