Replace PSA_KEY_ID_INIT macro

Replace the non-standard PSA_KEY_ID_INIT macro with PSA_KEY_ID_NULL
which is defined by the PSA Crypto API for the same purpose.

Signed-off-by: Balint Dobszay <balint.dobszay@arm.com>
Change-Id: I2fbf48e0a18e79535c95e79272ef3aa1a3cabb1f
diff --git a/components/service/crypto/include/psa/crypto_values.h b/components/service/crypto/include/psa/crypto_values.h
index 9fbea40..df3ac54 100644
--- a/components/service/crypto/include/psa/crypto_values.h
+++ b/components/service/crypto/include/psa/crypto_values.h
@@ -1769,6 +1769,9 @@
 
 #define PSA_KEY_LOCATION_VENDOR_FLAG            ((psa_key_location_t)0x800000)
 
+/** The null key identifier.
+ */
+#define PSA_KEY_ID_NULL                         ((psa_key_id_t)0)
 /** The minimum value for a key identifier chosen by the application.
  */
 #define PSA_KEY_ID_USER_MIN                     ((psa_key_id_t)0x00000001)