ecdh: simplify guards for the newly created PSA_HAVE_FULL_ECDH symbol

Signed-off-by: Valerio Setti <valerio.setti@nordicsemi.no>
diff --git a/include/mbedtls/config_psa.h b/include/mbedtls/config_psa.h
index 99ae7f3..7e6757c 100644
--- a/include/mbedtls/config_psa.h
+++ b/include/mbedtls/config_psa.h
@@ -887,8 +887,9 @@
 #define PSA_HAVE_FULL_JPAKE 1
 #endif
 
-#if defined(PSA_WANT_ALG_ECDH) && defined(PSA_WANT_KEY_TYPE_ECC_KEY_PAIR) && \
-    defined(PSA_WANT_KEY_TYPE_ECC_PUBLIC_KEY)
+/* Having suppor for ECDH implicitly includes support for private and
+ * public keys, so we don't specify that requirement here. */
+#if defined(PSA_WANT_ALG_ECDH)
 #define PSA_HAVE_FULL_ECDH 1
 #endif