HardwareIsolation: Added the error code

Added the error code which is specific to hardware isolation
interfaces.

Signed-off-by: Ramesh Iyyar <rameshi1@in.ibm.com>
Change-Id: I787bc1a422d197f016d0102f5ad659ab679f2b6e
diff --git a/yaml/xyz/openbmc_project/HardwareIsolation.errors.yaml b/yaml/xyz/openbmc_project/HardwareIsolation.errors.yaml
new file mode 100644
index 0000000..99e83d9
--- /dev/null
+++ b/yaml/xyz/openbmc_project/HardwareIsolation.errors.yaml
@@ -0,0 +1,2 @@
+- name: IsolatedAlready
+  description: The requested hardware is already isolated.