package/checkpolicy: add host gcc >= 5 dependency

Commit 56d9b887685c86fd4fbadda247cdbe733d499e81 forgot to add host
gcc >= 5 dependency

Fixes:
 - http://autobuild.buildroot.org/results/fc727efc0c658aaae55c83632a91af83701f0c49

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Signed-off-by: Yann E. MORIN <yann.morin.1998@free.fr>

package/checkpolicy/Config.in.host

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_HOST_CHECKPOLICY
 	bool "host checkpolicy"
+	depends on BR2_HOST_GCC_AT_LEAST_5 # host-libselinux -> host-libsepol
 	help
 	  checkpolicy is the SELinux policy compiler. It uses libsepol
 	  to generate the binary policy. checkpolicy uses the static
@@ -8,3 +9,6 @@ config BR2_PACKAGE_HOST_CHECKPOLICY
 	  shared library interface.
 
 	  http://selinuxproject.org/page/Main_Page
+
+comment "host checkpolicy needs a toolchain w/ host gcc >= 5"
+	depends on !BR2_HOST_GCC_AT_LEAST_5