Fix stupid typo in documentation
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index f1cfe75..1fe730c 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -278,7 +278,7 @@
 //#define MBEDTLS_AES_DECRYPT_ALT
 
 /**
- * \def MBEDTLS_EMTROPY_HARDWARE_ALT
+ * \def MBEDTLS_ENTROPY_HARDWARE_ALT
  *
  * Uncomment this macro to let mbed TLS use your own implementation of a
  * hardware entropy collector.