Ensure MBEDTLS_ECDSA_C is set when DETERMINISTIC_ECDSA is used

Ensure that MBEDTLS_ECDSA_C is set when PSA_WANT_ALG_DETERMINISTIC_ECDSA
is requested. Also added MBEDTLS_ECDSA_C to the requirements comment in
config.h for MBEDTLS_ECDSA_DETERMINISTIC.

Signed-off-by: John Durkop <john.durkop@fermatsoftware.com>
diff --git a/include/mbedtls/config.h b/include/mbedtls/config.h
index 6fbaeed..48e8855 100644
--- a/include/mbedtls/config.h
+++ b/include/mbedtls/config.h
@@ -864,7 +864,7 @@
  * may result in a compromise of the long-term signing key. This is avoided by
  * the deterministic variant.
  *
- * Requires: MBEDTLS_HMAC_DRBG_C
+ * Requires: MBEDTLS_HMAC_DRBG_C, MBEDTLS_ECDSA_C
  *
  * Comment this macro to disable deterministic ECDSA.
  */