Change the value type in the mbedtls_platform_random_in_range()

Signed-off-by: Piotr Nowicki <piotr.nowicki@arm.com>
diff --git a/include/mbedtls/platform_util.h b/include/mbedtls/platform_util.h
index 81d0f0f..a5b95ae 100644
--- a/include/mbedtls/platform_util.h
+++ b/include/mbedtls/platform_util.h
@@ -264,7 +264,7 @@
  *
  * \return      The generated random number.
  */
-uint32_t mbedtls_platform_random_in_range( size_t num );
+uint32_t mbedtls_platform_random_in_range( uint32_t num );
 
 /**
  * \brief       Random delay function.