Bump buidlroot version to 2018.02.6

bsp/buildroot/package/kvm-unit-tests/Config.in

@@ -1,16 +1,22 @@
+config BR2_PACKAGE_KVM_UNIT_TESTS_ARCH_SUPPORTS
+	bool
+	# On ARM, it uses virtualization extensions
+	default y if BR2_cortex_a7 || BR2_cortex_a12 || \
+		BR2_cortex_a15 || BR2_cortex_a15_a7 || \
+		BR2_cortex_a17 || BR2_cortex_a17_a7
+	default y if BR2_i386 || BR2_x86_64
+	default y if BR2_powerpc64 || BR2_powerpc64le
+
 config BR2_PACKAGE_KVM_UNIT_TESTS
 	bool "kvm-unit-tests"
-	select BR2_HOSTARCH_NEEDS_IA32_COMPILER if BR2_x86_64=y
+	depends on BR2_PACKAGE_KVM_UNIT_TESTS_ARCH_SUPPORTS
 	# on i386 and x86-64, __builtin_reachable is used, so we need
 	# gcc 4.5 at least. on i386, we use the target gcc, while on
 	# x86-64 we use the host gcc (see .mk file for details)
-	# On ARM, it uses virtualization extensions
-	depends on BR2_cortex_a7 || BR2_cortex_a12 || \
-		BR2_cortex_a15 || BR2_cortex_a17 || \
-		(BR2_i386 && BR2_TOOLCHAIN_GCC_AT_LEAST_4_5) || \
-		BR2_powerpc64 || \
-		BR2_powerpc64le || \
-		(BR2_x86_64 && BR2_HOST_GCC_AT_LEAST_4_5)
+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_4_5 || !BR2_i386
+	depends on BR2_HOST_GCC_AT_LEAST_4_5 || !BR2_x86_64
+	depends on BR2_HOSTARCH = "x86_64" || !BR2_x86_64
+	select BR2_HOSTARCH_NEEDS_IA32_COMPILER if BR2_x86_64=y
 	help
 	  kvm-unit-tests is a project as old as KVM. As its name
 	  suggests, it's purpose is to provide unit tests for KVM. The
@@ -28,3 +34,11 @@ config BR2_PACKAGE_KVM_UNIT_TESTS
 	  features are submitted with accompanying unit tests.
 
 	  http://www.linux-kvm.org/page/KVM-unit-tests
+
+comment "kvm-unit-tests needs a toolchain w/ gcc >= 4.5"
+	depends on BR2_i386
+	depends on !BR2_TOOLCHAIN_GCC_AT_LEAST_4_5
+
+comment "kvm-unit-tests needs a host gcc >= 4.5"
+	depends on BR2_x86_64
+	depends on !BR2_HOST_GCC_AT_LEAST_4_5