systemd: needs kernel headers >= 3.10

Systemd needs a toolchain with kernel headers >= 3.10, as it needs
IFLA_VLAN_PROTOCOL from linux/if_link.h.

Fixes: http://autobuild.buildroot.net/results/33e/33e1447949d13bccc4076b69f902432e2131cc1c

Signed-off-by: Eric Le Bihan <eric.le.bihan.dev@free.fr>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

system/Config.in

@@ -96,12 +96,12 @@ config BR2_INIT_SYSTEMD
 	depends on BR2_TOOLCHAIN_HAS_SSP
 	depends on BR2_USE_MMU
 	depends on !BR2_PREFER_STATIC_LIB
-	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_8
+	depends on BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10
 	select BR2_PACKAGE_SYSTEMD
 
-comment 'systemd needs an (e)glibc toolchain, headers >= 3.8'
+comment 'systemd needs an (e)glibc toolchain, headers >= 3.10'
 	depends on !(BR2_TOOLCHAIN_USES_GLIBC \
-		&& BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_8)
+		&& BR2_TOOLCHAIN_HEADERS_AT_LEAST_3_10)
 
 config BR2_INIT_NONE
 	bool "None"