bios: Add/remove bios attributes

A) Adding three bios attributes to the supported list. Newly
added bios attributes are:
1. pvm_system_operating_mode
2. pvm_rpa_boot_mode
3. pvm_os_ipl_type

B) Removed the unused bios attribute 'pvm_os_boot_side'.

Tested by:
Verified the values using the pldmtool, redfish and hyperviosr
macro.

1. pldmtool bios GetBIOSTable -t 1
    {
        "AttributeHandle": 23,
        "AttributeNameHandle": "41(pvm_system_operating_mode)",
        "AttributeType": "BIOSEnumeration",
        "NumberOfPossibleValues": 2,
        "PossibleValueStringHandle[0]": "15(Normal)",
        "PossibleValueStringHandle[1]": "14(Manual)",
        "NumberOfDefaultValues": 1,
        "DefaultValueStringHandleIndex[0]": 0,
        "StringHandle": "15(Normal)"
    },
    {
        "AttributeHandle": 24,
        "AttributeNameHandle": "36(pvm_rpa_boot_mode)",
        "AttributeType": "BIOSEnumeration",
        "NumberOfPossibleValues": 6,
        "PossibleValueStringHandle[0]": "15(Normal)",
        "PossibleValueStringHandle[1]": "23(SavedList)",
        "PossibleValueStringHandle[2]": "24(SmsMenu)",
        "PossibleValueStringHandle[3]": "18(OkPrompt)",
        "PossibleValueStringHandle[4]": "7(DefaultList)",
        "PossibleValueStringHandle[5]": "19(PblBootLid)",
        "NumberOfDefaultValues": 1,
        "DefaultValueStringHandleIndex[0]": 0,
        "StringHandle": "15(Normal)"
    },
    {
        "AttributeHandle": 25,
        "AttributeNameHandle": "34(pvm_os_ipl_type)",
        "AttributeType": "BIOSEnumeration",
        "NumberOfPossibleValues": 4,
        "PossibleValueStringHandle[0]": "1(A_Mode)",
        "PossibleValueStringHandle[1]": "4(B_Mode)",
        "PossibleValueStringHandle[2]": "5(C_Mode)",
        "PossibleValueStringHandle[3]": "6(D_Mode)",
        "NumberOfDefaultValues": 1,
        "DefaultValueStringHandleIndex[0]": 3,
        "StringHandle": "6(D_Mode)"
    }

2. pldmtool bios GetBIOSTable -t 2
    {
        "AttributeHandle": 23,
        "AttributeType": "BIOSEnumeration",
        "NumberOfCurrentValues": 1,
        "CurrentValueStringHandleIndex[0]": "Normal"
    },
    {
        "AttributeHandle": 24,
        "AttributeType": "BIOSEnumeration",
        "NumberOfCurrentValues": 1,
        "CurrentValueStringHandleIndex[0]": "Normal"
    },
    {
        "AttributeHandle": 25,
        "AttributeType": "BIOSEnumeration",
        "NumberOfCurrentValues": 1,
        "CurrentValueStringHandleIndex[0]": "D_Mode"
    }
3. GET https://${bmc}/redfish/v1/Systems/system/Bios
    "pvm_os_ipl_type": "D_Mode",
    "pvm_rpa_boot_mode": "Normal",
    "pvm_system_operating_mode": "Normal",

Signed-off-by: Jayashankar Padath <jayashankar.padath@in.ibm.com>
Change-Id: Id2bc14f1825ea3e62899d6a749b740cd67bf4d60