tests: Add mbedtls_test_ prefix to *hexify functions

Add mbedtls_test_ prefix to hexify() and unhexify()
test helper functions.

Command to change *.function files:
find . -name "*.function" -exec awk -i inplace \
    '{sub(/(un|)hexify\>/,"mbedtls_test_&")}1' {} \;

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/tests/suites/test_suite_aes.function b/tests/suites/test_suite_aes.function
index da8c1e9..9734aa0 100644
--- a/tests/suites/test_suite_aes.function
+++ b/tests/suites/test_suite_aes.function
@@ -340,9 +340,9 @@
     TEST_ASSERT( strlen( hex_src_string ) <= ( 64 * 2 ) );
     TEST_ASSERT( strlen( hex_dst_string ) <= ( 64 * 2 ) );
 
-    key_len = unhexify( key_str, hex_key_string );
-    unhexify( iv_str, hex_iv_string );
-    in_buffer_len = unhexify( src_str, hex_src_string );
+    key_len = mbedtls_test_unhexify( key_str, hex_key_string );
+    mbedtls_test_unhexify( iv_str, hex_iv_string );
+    in_buffer_len = mbedtls_test_unhexify( src_str, hex_src_string );
 
     TEST_ASSERT( mbedtls_aes_setkey_enc( &ctx, key_str, key_len * 8 ) == 0 );
     src_str_next = src_str;
@@ -352,7 +352,7 @@
         TEST_ASSERT( mbedtls_aes_crypt_ofb( &ctx, fragment_size, &iv_offset,
                                             iv_str, src_str_next, output ) == 0 );
 
-        hexify( dst_str, output, fragment_size );
+        mbedtls_test_hexify( dst_str, output, fragment_size );
         TEST_ASSERT( strncmp( (char *) dst_str, hex_dst_string,
                               ( 2 * fragment_size ) ) == 0 );