Adding support for GetDatetime BIOS command in pldmtool.

./pldmtool -h
PLDM requester tool for OpenBMC
Usage: ./pldmtool [OPTIONS] SUBCOMMAND

Options:
  -h,--help                   Print this help message and exit

Subcommands:
  raw                         send a raw request and print response
  base                        base type command
  bios                        bios type command

./pldmtool bios -h
bios type command
Usage: ./pldmtool bios [OPTIONS] SUBCOMMAND

Options:
  -h,--help                   Print this help message and exit

Subcommands:
  GetDateTime                 get date time

./pldmtool bios GetDateTime
Encode request successfully
Request Message:
08 01 80 03 0c
Success in creating the socket : RC = 3
Success in connecting to socket : RC = 0
Success in sending message type as pldm to mctp : RC = 0
Write to socket successful : RC = 5
Total length:5
Loopback response message:
08 01 80 03 0c
On first recv(),response == request : RC = 0
Total length: 13
Shutdown Socket successful :  RC = 0
Response Message:
08 01 00 03 0c 00 01 05 12 11 12 19 20
Date & Time :
DD-MM-YYYY HH:MM:SS - 11-12-2019 12:05:01

Signed-off-by: Sridevi Ramesh <sridevra@in.ibm.com>
Change-Id: If12ddc7da19ae2c810b6c8cd99177efa1b6113ad
diff --git a/tool/pldm_bios_cmd.hpp b/tool/pldm_bios_cmd.hpp
new file mode 100644
index 0000000..4448f7e
--- /dev/null
+++ b/tool/pldm_bios_cmd.hpp
@@ -0,0 +1,14 @@
+#pragma once
+
+#include <CLI/CLI.hpp>
+
+namespace pldmtool
+{
+
+namespace bios
+{
+
+void registerCommand(CLI::App& app);
+}
+
+} // namespace pldmtool