tpm2-tools: propagate dependencies of selected packages

- C++ (tpm2-tss)
- MMU (dbus, libglib)
- threads (libglib)
- wchar (libglib -> gettext)

Fixes (libglib):
  http://autobuild.buildroot.net/results/786859fccc477de1519d85d8a180626bb8ebe062
  http://autobuild.buildroot.net/results/df6518f331c16b477c6e934914d0e56dc102c228

[Peter: add C++ dependency to config option]
Signed-off-by: Baruch Siach <baruch@tkos.co.il>
Signed-off-by: Carlos Santos <casantos@datacom.ind.br>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/tpm2-tools/Config.in

@@ -1,5 +1,9 @@
 config BR2_PACKAGE_TPM2_TOOLS
 	bool "tpm2-tools"
+	depends on BR2_INSTALL_LIBSTDCPP # tpm2-tss
+	depends on BR2_USE_MMU # dbus, libglib
+	depends on BR2_USE_WCHAR # libglib -> gettext
+	depends on BR2_TOOLCHAIN_HAS_THREADS # libglib
 	select BR2_PACKAGE_DBUS
 	select BR2_PACKAGE_LIBCURL
 	select BR2_PACKAGE_LIBGLIB2
@@ -14,3 +18,8 @@ config BR2_PACKAGE_TPM2_TOOLS
 	  implementation.
 
 	  https://github.com/tpm2-software/tpm2-tools
+
+comment "tpm2-tools needs a toolchain w/ C++, wchar, threads"
+	depends on BR2_USE_MMU
+	depends on !BR2_INSTALL_LIBSTDCPP || !BR2_USE_WCHAR \
+		|| !BR2_TOOLCHAIN_HAS_THREADS