Expose the CONFIG_TCG selector to let minikconf.py uses it.

When building with --disable-tcg build, this helps to deselect
devices that are TCG-dependent.

Reviewed-by: Richard Henderson <richard.henderson@linaro.org>
Reviewed-by: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 Makefile      | 1 +
 accel/Kconfig | 3 +++
 2 files changed, 4 insertions(+)

diff --git a/Makefile b/Makefile
index 7c055a9e32..aef466b0b9 100644
--- a/Makefile
+++ b/Makefile
@@ -405,6 +405,7 @@ endif
 MINIKCONF_ARGS = \
     $(CONFIG_MINIKCONF_MODE) \
     $@ $*/config-devices.mak.d $< $(MINIKCONF_INPUTS) \
+    CONFIG_TCG=$(CONFIG_TCG) \
     CONFIG_KVM=$(CONFIG_KVM) \
     CONFIG_SPICE=$(CONFIG_SPICE) \
     CONFIG_IVSHMEM=$(CONFIG_IVSHMEM) \
diff --git a/accel/Kconfig b/accel/Kconfig
index c21802bb49..2ad94a3839 100644
--- a/accel/Kconfig
+++ b/accel/Kconfig
@@ -1,3 +1,6 @@
+config TCG
+    bool
+
 config KVM
     bool
 
-- 
2.21.3