psa: cipher: Remove unused `key_set` operation field

Signed-off-by: Ronald Cron <ronald.cron@arm.com>
diff --git a/include/psa/crypto_struct.h b/include/psa/crypto_struct.h
index 87eefb9..3ccad24 100644
--- a/include/psa/crypto_struct.h
+++ b/include/psa/crypto_struct.h
@@ -144,7 +144,6 @@
 struct psa_cipher_operation_s
 {
     psa_algorithm_t alg;
-    unsigned int key_set : 1;
     unsigned int iv_required : 1;
     unsigned int iv_set : 1;
     unsigned int mbedtls_in_use : 1; /* Indicates mbed TLS is handling the operation. */
@@ -158,7 +157,7 @@
     } ctx;
 };
 
-#define PSA_CIPHER_OPERATION_INIT {0, 0, 0, 0, 0, 0, 0, {0}}
+#define PSA_CIPHER_OPERATION_INIT {0, 0, 0, 0, 0, 0, {0}}
 static inline struct psa_cipher_operation_s psa_cipher_operation_init( void )
 {
     const struct psa_cipher_operation_s v = PSA_CIPHER_OPERATION_INIT;