MBEDTLS_GCM_C macro

\def MBEDTLS_ERROR_C Enable error code to error string conversion. Module: library/error.c Caller: This module enables mbedtls_strerror(). \def MBEDTLS_GCM_C Enable the Galois/Counter Mode (GCM) for AES. Module: library/gcm.c Requires: MBEDTLS_AES_C or MBEDTLS_CAMELLIA_C This module enables the AES-GCM and CAMELLIA-GCM ciphersuites, if other requisites are enabled as well.