Replace all inclusions of config.h

Also remove preprocessor logic for MBEDTLS_CONFIG_FILE, since
build_info.h alreadyy handles it.

This commit was generated using the following script:

# ========================
#!/bin/sh
git ls-files | grep -v '^include/mbedtls/build_info\.h$' | xargs sed -b -E -i '
/^#if !?defined\(MBEDTLS_CONFIG_FILE\)/i#include "mbedtls/build_info.h"
//,/^#endif/d
'
# ========================

Signed-off-by: Bence Szépkúti <bence.szepkuti@arm.com>
diff --git a/include/mbedtls/md.h b/include/mbedtls/md.h
index 7bf8213..1170bc1 100644
--- a/include/mbedtls/md.h
+++ b/include/mbedtls/md.h
@@ -28,11 +28,7 @@
 
 #include <stddef.h>
 
-#if !defined(MBEDTLS_CONFIG_FILE)
-#include "mbedtls/config.h"
-#else
-#include MBEDTLS_CONFIG_FILE
-#endif
+#include "mbedtls/build_info.h"
 
 #define MBEDTLS_ERR_MD_FEATURE_UNAVAILABLE                -0x5080  /**< The selected feature is not available. */
 #define MBEDTLS_ERR_MD_BAD_INPUT_DATA                     -0x5100  /**< Bad input parameters to function. */