tools: fix build without LIBCRYPTO support

Commit cb9faa6f98ae ("tools: Use a single target-independent config to
enable OpenSSL") introduced a target-independent configuration to build
crypto features in host tools.

But since commit 2c21256b27d7 ("hash: Use Kconfig to enable hashing in
host tools and SPL") the build without OpenSSL is broken, due to FIT
signature/encryption features. Add missing conditional compilation
tokens to fix this.

Signed-off-by: Paul-Erwan Rio <paulerwan.rio@gmail.com>
Tested-by: Alexander Dahl <ada@thorsis.com>
Cc: Simon Glass <sjg@chromium.org>
Reviewed-by: Tom Rini <trini@konsulko.com>
Reviewed-by: Simon Glass <sjg@chromium.org>
diff --git a/tools/Kconfig b/tools/Kconfig
index f8632cd..f01ed78 100644
--- a/tools/Kconfig
+++ b/tools/Kconfig
@@ -51,6 +51,7 @@
 	  Support the rsassa-pss signature scheme in the tools builds
 
 config TOOLS_FIT_SIGNATURE
+	depends on TOOLS_LIBCRYPTO
 	def_bool y
 	help
 	  Enable signature verification of FIT uImages in the tools builds