Cleanup following the removal of MBEDTLS_BIGNUM_C option

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/include/mbedtls/mbedtls_config.h b/include/mbedtls/mbedtls_config.h
index b7a869a..b1e30ab 100644
--- a/include/mbedtls/mbedtls_config.h
+++ b/include/mbedtls/mbedtls_config.h
@@ -1043,7 +1043,7 @@
  *
  * Requires: MBEDTLS_ASN1_PARSE_C, MBEDTLS_PK_PARSE_C,
  *           MBEDTLS_X509_CRT_PARSE_C MBEDTLS_X509_CRL_PARSE_C,
- *           MBEDTLS_BIGNUM_C, MBEDTLS_MD_C
+ *           MBEDTLS_MD_C
  *
  * This module is required for the PKCS #7 parsing modules.
  */
@@ -1056,7 +1056,7 @@
  *
  * Module:  library/x509_create.c
  *
- * Requires: MBEDTLS_BIGNUM_C, MBEDTLS_PK_PARSE_C,
+ * Requires: MBEDTLS_ASN1_WRITE_C, MBEDTLS_PK_PARSE_C
  *
  * \warning You must call psa_crypto_init() before doing any X.509 operation.
  *
@@ -1188,7 +1188,7 @@
  *          library/x509_crt.c
  *          library/x509_csr.c
  *
- * Requires: MBEDTLS_ASN1_PARSE_C, MBEDTLS_BIGNUM_C, MBEDTLS_PK_PARSE_C
+ * Requires: MBEDTLS_ASN1_PARSE_C, MBEDTLS_PK_PARSE_C
  *
  * \warning You must call psa_crypto_init() before doing any X.509 operation.
  *