Remove blank line

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/include/psa/crypto_extra.h b/include/psa/crypto_extra.h
index 9f46c5f..7074090 100644
--- a/include/psa/crypto_extra.h
+++ b/include/psa/crypto_extra.h
@@ -1,5 +1,4 @@
 /**
-
  * \file psa/crypto_extra.h
  *
  * \brief PSA cryptography module: Mbed TLS vendor extensions