Rename config.h to mbedtls_config.h

This commit was generated using the following script:

# ========================
#!/bin/sh
git ls-files | grep -v '^ChangeLog' | xargs sed -b -E -i '
s/((check|crypto|full|mbedtls|query)_config)\.h/\1\nh/g
s/config\.h/mbedtls_config.h/g
y/\n/./
'
mv include/mbedtls/config.h include/mbedtls/mbedtls_config.h
# ========================

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
diff --git a/library/net_sockets.c b/library/net_sockets.c
index 5fbe1f7..17a9e4a 100644
--- a/library/net_sockets.c
+++ b/library/net_sockets.c
@@ -18,7 +18,7 @@
  */
 
 /* Enable definition of getaddrinfo() even when compiling with -std=c99. Must
- * be set before config.h, which pulls in glibc's features.h indirectly.
+ * be set before mbedtls_config.h, which pulls in glibc's features.h indirectly.
  * Harmless on other platforms. */
 #ifndef _POSIX_C_SOURCE
 #define _POSIX_C_SOURCE 200112L
@@ -34,7 +34,7 @@
 #if !defined(unix) && !defined(__unix__) && !defined(__unix) && \
     !defined(__APPLE__) && !defined(_WIN32) && !defined(__QNXNTO__) && \
     !defined(__HAIKU__) && !defined(__midipix__)
-#error "This module only works on Unix and Windows, see MBEDTLS_NET_C in config.h"
+#error "This module only works on Unix and Windows, see MBEDTLS_NET_C in mbedtls_config.h"
 #endif
 
 #if defined(MBEDTLS_PLATFORM_C)