Added new testcases for Cipher suite IPMI cmd.

Testcases covered in this script:
    1) Verify cipher suite IPMI raw cmd for all available channels
including channel 14(current channel).

    2) Verify cipher suite IPMI raw cmd for invalid channels and expects
response code 0xcc.

    3) Verify cipher suite IPMI raw cmd with one byte more and less for
valid channel and expects response code as 0xc7.

Added keyword on lib/ipmi_client.robot to check invalid ipmi cmd.

Added keyword to get invalid channel list in lib/bmc_network_utils.robot.

Tested: Run robot ipmi/test_ipmi_cipher.robot

Signed-off-by: Nagarjun B  <nagarjunb@ami.com>
Change-Id: Id510a6a7bb4c58770fdd04b32bf5ae9f276e2f39
diff --git a/lib/ipmi_client.robot b/lib/ipmi_client.robot
index 8bee9da..52e46c7 100755
--- a/lib/ipmi_client.robot
+++ b/lib/ipmi_client.robot
@@ -560,3 +560,16 @@
     ${resp}=  Split String  ${resp}
 
     [Return]  ${resp}
+
+
+Verify Invalid IPMI Command
+    [Documentation]  Execute invalid IPMI command and verify with given response code.
+    [Arguments]  ${ipmi_cmd}  ${error_code}=0xc9
+
+    #  Description Of Arguments.
+    #  ${ipmi_cmd}   - IPMI raw cmd with invalid data length.
+    #  ${error_code} - Expected error code e.g 0xc7, 0xcc.
+
+    ${resp}=  Run External IPMI Raw Command  ${ipmi_cmd}  fail_on_err=0
+
+    Should Contain  ${resp}  rsp=${error_code}