package/sdbusplus: needs C++17

sdbusplus needs C++17 since
https://github.com/openbmc/sdbusplus/commit/ca46b9d2e958d1e4b392265f656f782899c2de1d

This is not needed for host-sdbusplus as libsdbusplus is disabled on
host through --disable-libsdbusplus

Fixes:
 - http://autobuild.buildroot.org/results/65a4652e5b419f03ace109c4b3738e9b997cdabe

Signed-off-by: Fabrice Fontaine <fontaine.fabrice@gmail.com>
Reviewed-by: John Faith <jfaith@impinj.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>
(cherry picked from commit d127c5e4eafe828160b980f79630040bae7c9b95)
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/sdbusplus/Config.in

@@ -2,6 +2,7 @@ config BR2_PACKAGE_SDBUSPLUS
 	bool "sdbusplus"
 	depends on BR2_INSTALL_LIBSTDCPP
 	depends on BR2_PACKAGE_SYSTEMD
+	depends on BR2_TOOLCHAIN_GCC_AT_LEAST_7 # C++17
 	help
 	  A C++ library for sd-bus with a bindings and doc generator.
 
@@ -10,5 +11,6 @@ config BR2_PACKAGE_SDBUSPLUS
 
 	  https://github.com/openbmc/sdbusplus
 
-comment "sdbusplus needs systemd and a toolchain w/ C++"
-	depends on !BR2_PACKAGE_SYSTEMD || !BR2_INSTALL_LIBSTDCPP
+comment "sdbusplus needs systemd and a toolchain w/ C++, gcc >= 7"
+	depends on !BR2_PACKAGE_SYSTEMD || !BR2_INSTALL_LIBSTDCPP || \
+		!BR2_TOOLCHAIN_GCC_AT_LEAST_7