Add interface to assign privilege to groups

This interface will be implemented to assign privilege roles to
groups. The privilege roles will be assigned to groups
and the user accounts which are part of the group will inherit
the privilege role.

Change-Id: I2326de5f7f3e6e92c2a0d7648a5677b33a0b1db0
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
diff --git a/xyz/openbmc_project/User/Common.errors.yaml b/xyz/openbmc_project/User/Common.errors.yaml
index ccca302..2bcfb38 100644
--- a/xyz/openbmc_project/User/Common.errors.yaml
+++ b/xyz/openbmc_project/User/Common.errors.yaml
@@ -13,3 +13,6 @@
 # xyz.openbmc_project.User.Common.Error.NoResource
 - name: NoResource
   description: No resource available.
+# xyz.openbmc_project.User.Common.Error.PrivilegeMappingExists
+- name: PrivilegeMappingExists
+  description: Specified privilege mapping already exists.
\ No newline at end of file