IPMI LAN channel cipher access list

Changes:
   - Added new function to get channel cipher access list.
   - Update corresponding test case.

The changes doesn't impact upstream IPMI tool output.

O/p of the ipmitool "channel getciphers ipmi":
ID   IANA    Auth Alg        Integrity Alg   Confidentiality Alg
3    N/A     hmac_sha1       hmac_sha1_96    aes_cbc_128
17   N/A     hmac_sha256     sha256_128      aes_cbc_128

Change-Id: I72e1e5bad909ff3c854f79c929f9df5139b0ac33
Signed-off-by: George Keishing <gkeishin@in.ibm.com>
diff --git a/data/ipmi_raw_cmd_table.py b/data/ipmi_raw_cmd_table.py
index 2fc793e..3d3dd65 100644
--- a/data/ipmi_raw_cmd_table.py
+++ b/data/ipmi_raw_cmd_table.py
@@ -7,12 +7,12 @@
 
 """
 
-# The currently supported cipher level list.
+# The currently supported cipher list.
 # Refer:
 # openbmc/meta-openbmc-machines/meta-openpower/meta-ibm/meta-witherspoon/recipe
 # s-phosphor/ipmi/phosphor-ipmi-host/cipher_list.json
-valid_cipher_list = [3, 17]
-unsupported_cipher_list = [1, 2, 15, 16]
+valid_ciphers = ['3', '17']
+unsupported_ciphers = ['1', '2', '15', '16']
 
 IPMI_RAW_CMD = {
     # Interface name