Rename ssl_cli/srv.c

Rename ssl_cli.c and ssl_srv.c to reflect the fact
that they are TLS 1.2 specific now. Align there new
names with the TLS 1.3 ones.

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/tests/scripts/all.sh b/tests/scripts/all.sh
index 69b1fc8..e732ae4 100755
--- a/tests/scripts/all.sh
+++ b/tests/scripts/all.sh
@@ -2169,14 +2169,14 @@
 }
 
 component_build_no_ssl_srv () {
-    msg "build: full config except ssl_srv.c, make, gcc" # ~ 30s
+    msg "build: full config except SSL server, make, gcc" # ~ 30s
     scripts/config.py full
     scripts/config.py unset MBEDTLS_SSL_SRV_C
     make CC=gcc CFLAGS='-Werror -Wall -Wextra -O1'
 }
 
 component_build_no_ssl_cli () {
-    msg "build: full config except ssl_cli.c, make, gcc" # ~ 30s
+    msg "build: full config except SSL client, make, gcc" # ~ 30s
     scripts/config.py full
     scripts/config.py unset MBEDTLS_SSL_CLI_C
     make CC=gcc CFLAGS='-Werror -Wall -Wextra -O1'