cleanup: move core functions to core pkg

as we are refractoring the cephfs code,
Moving all the core functions to a new folder
/pkg called core. This will make things easier
to implement. For now onwards all the core
functionalities will be added to the core
package.

Signed-off-by: Madhu Rajanna <madhupr007@gmail.com>

internal/cephfs/util/util.go

@@ -0,0 +1,49 @@
+/*
+Copyright 2018 The Ceph-CSI Authors.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+package util
+
+import (
+	"context"
+	"time"
+
+	"github.com/ceph/ceph-csi/internal/util/log"
+
+	"github.com/golang/protobuf/ptypes"
+	"github.com/golang/protobuf/ptypes/timestamp"
+)
+
+// VolumeID string representation.
+type VolumeID string
+
+const (
+	// VolIDVersion is the version number of volume ID encoding scheme.
+	VolIDVersion uint16 = 1
+
+	// RadosNamespace to store CSI specific objects and keys.
+	RadosNamespace = "csi"
+)
+
+func ParseTime(ctx context.Context, createTime time.Time) (*timestamp.Timestamp, error) {
+	tm, err := ptypes.TimestampProto(createTime)
+	if err != nil {
+		log.ErrorLog(ctx, "failed to convert time %s %v", createTime, err)
+
+		return tm, err
+	}
+
+	return tm, nil
+}