refactor ssl related code into ssl.c

Signed-off-by: Andy Green <andy.green@linaro.org>
diff --git a/CMakeLists.txt b/CMakeLists.txt
index bd052c5..78cb7db 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -276,6 +276,12 @@
 		)
 endif()
 
+if (LWS_WITH_SSL)
+	list(APPEND SOURCES
+		lib/ssl.c
+		)
+endif()
+
 # select the active platform files
 
 if (WIN32)