Update the MSBuild toolset versions to VS2017

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
diff --git a/scripts/generate_visualc_files.pl b/scripts/generate_visualc_files.pl
index 272337c..a0dfc57 100755
--- a/scripts/generate_visualc_files.pl
+++ b/scripts/generate_visualc_files.pl
@@ -1,7 +1,7 @@
 #!/usr/bin/env perl
 
 # Generate main file, individual apps and solution files for
-# MS Visual Studio 2013
+# MS Visual Studio 2017
 #
 # Must be run from Mbed TLS root or scripts directory.
 # Takes no argument.