accel/Kconfig: Add the TCG selector

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>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

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) \

accel/Kconfig

+config TCG
+    bool
+
 config KVM
     bool