Remove spurious extern "C"

This header only contains preprocessor definitions. They are not affected by
extern "C".

Signed-off-by: Gilles Peskine <Gilles.Peskine@arm.com>
diff --git a/include/mbedtls/config_psa.h b/include/mbedtls/config_psa.h
index 303758f..9823fa3 100644
--- a/include/mbedtls/config_psa.h
+++ b/include/mbedtls/config_psa.h
@@ -44,10 +44,6 @@
 
 #include "psa/crypto_legacy.h"
 
-#ifdef __cplusplus
-extern "C" {
-#endif
-
 
 
 /****************************************************************/
@@ -1074,8 +1070,4 @@
 #define PSA_WANT_KEY_TYPE_PASSWORD_HASH 1
 #define PSA_WANT_KEY_TYPE_RAW_DATA 1
 
-#ifdef __cplusplus
-}
-#endif
-
 #endif /* MBEDTLS_CONFIG_PSA_H */