remove redundant include

Remove redunadnat include for platform.h which was acciddently pushed,
for debugging purposes
diff --git a/library/ecdsa.c b/library/ecdsa.c
index d95dcae..8804ca6 100644
--- a/library/ecdsa.c
+++ b/library/ecdsa.c
@@ -37,7 +37,6 @@
 #include "mbedtls/asn1write.h"
 
 #include <string.h>
-#include "mbedtls/platform.h"
 #if defined(MBEDTLS_ECDSA_DETERMINISTIC)
 #include "mbedtls/hmac_drbg.h"
 #endif