tools: add mksunxiboot to tools-all target

mksunxiboot is useful outside of u-boot, it is e.g. used by sunxi-tools.

Signed-off-by: Stefan Brüns <stefan.bruens@rwth-aachen.de>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
diff --git a/tools/Makefile b/tools/Makefile
index 556f397..400588c 100644
--- a/tools/Makefile
+++ b/tools/Makefile
@@ -13,6 +13,7 @@
 CONFIG_XWAY_SWAP_BYTES = y
 CONFIG_NETCONSOLE = y
 CONFIG_SHA1_CHECK_UB_IMG = y
+CONFIG_SUNXI = y
 endif
 
 subdir-$(HOST_TOOLS_ALL) += easylogo