Adding dbus interfaces for channel access info

Added new interface(ChannelAccess) for holding channel
access information(privilege). This is used to set & get
channel level authorization.

Change-Id: Ib927d5658c0601df0da0969572fa28733a825b93
Signed-off-by: AppaRao Puli <apparao.puli@intel.com>
Signed-off-by: Richard Marian Thomaiyar <richard.marian.thomaiyar@linux.intel.com>

Author: apuli1

xyz/openbmc_project/Channel/ChannelAccess.interface.yaml

@@ -0,0 +1,13 @@
+description: >
+    This interface defines channel specific privilege access information
+    which is used for channel authorization. Application must determine
+    channel level privilege restriction based on this property.
+
+properties:
+    - name: MaxPrivilege
+      type: string
+      description: >
+          Maximum privilege associated with specific channel.
+      errors:
+        - xyz.openbmc_project.Common.Error.InvalidArgument
+        - xyz.openbmc_project.Common.Error.InternalFailure