Replace ITS specific types with more generic PSA storage types

PSA spec now defines more generic PSA storage types instead of the ITS
specific ones. This is necessary in order to integrate with
the newer implementation of PSA ITS landing in Mbed OS soon.
Changes include the following:
- psa_status_t replaces psa_its_status_t
- psa_storage_info_t replaces psa_its_info_t
- psa_storage_uid_t replaces psa_its_uid_t
diff --git a/library/psa_crypto.c b/library/psa_crypto.c
index fd9f387..1efb3e8 100644
--- a/library/psa_crypto.c
+++ b/library/psa_crypto.c
@@ -4391,45 +4391,11 @@
 
 #if ( defined(MBEDTLS_ENTROPY_NV_SEED) && defined(MBEDTLS_PSA_HAS_ITS_IO) )
 
-/* Support function for error conversion between psa_its error codes to psa crypto */
-static psa_status_t its_to_psa_error( psa_its_status_t ret )
-{
-    switch( ret )
-    {
-        case PSA_ITS_SUCCESS:
-            return( PSA_SUCCESS );
-
-        case PSA_ITS_ERROR_UID_NOT_FOUND:
-            return( PSA_ERROR_DOES_NOT_EXIST );
-
-        case PSA_ITS_ERROR_STORAGE_FAILURE:
-            return( PSA_ERROR_STORAGE_FAILURE );
-
-        case PSA_ITS_ERROR_INSUFFICIENT_SPACE:
-            return( PSA_ERROR_INSUFFICIENT_STORAGE );
-
-        case PSA_ITS_ERROR_OFFSET_INVALID:
-        case PSA_ITS_ERROR_INCORRECT_SIZE:
-        case PSA_ITS_ERROR_INVALID_ARGUMENTS:
-            return( PSA_ERROR_INVALID_ARGUMENT );
-
-        case PSA_ITS_ERROR_FLAGS_NOT_SUPPORTED:
-            return( PSA_ERROR_NOT_SUPPORTED );
-
-        case PSA_ITS_ERROR_WRITE_ONCE:
-            return( PSA_ERROR_ALREADY_EXISTS );
-
-        default:
-            return( PSA_ERROR_GENERIC_ERROR );
-    }
-}
-
 psa_status_t mbedtls_psa_inject_entropy( const unsigned char *seed,
                                          size_t seed_size )
 {
     psa_status_t status;
-    psa_its_status_t its_status;
-    struct psa_its_info_t p_info;
+    struct psa_storage_info_t p_info;
     if( global_data.initialized )
         return( PSA_ERROR_NOT_PERMITTED );
 
@@ -4438,15 +4404,13 @@
           ( seed_size > MBEDTLS_ENTROPY_MAX_SEED_SIZE ) )
             return( PSA_ERROR_INVALID_ARGUMENT );
 
-    its_status = psa_its_get_info( PSA_CRYPTO_ITS_RANDOM_SEED_UID, &p_info );
-    status = its_to_psa_error( its_status );
+    status = psa_its_get_info( PSA_CRYPTO_ITS_RANDOM_SEED_UID, &p_info );
 
-    if( PSA_ITS_ERROR_UID_NOT_FOUND == its_status ) /* No seed exists */
+    if( PSA_ERROR_DOES_NOT_EXIST == status ) /* No seed exists */
     {
-        its_status = psa_its_set( PSA_CRYPTO_ITS_RANDOM_SEED_UID, seed_size, seed, 0 );
-        status = its_to_psa_error( its_status );
+        status = psa_its_set( PSA_CRYPTO_ITS_RANDOM_SEED_UID, seed_size, seed, 0 );
     }
-    else if( PSA_ITS_SUCCESS == its_status )
+    else if( PSA_SUCCESS == status )
     {
         /* You should not be here. Seed needs to be injected only once */
         status = PSA_ERROR_NOT_PERMITTED;