nvidia-oem: Implement GetRedfishServicePort

This command is used by BIOS before creating SMBIOS record
type 42. BIOS gets USBDescription information from BMC.

Note:
The implementation in this PR is for
RedfishServiceUUID.
The support for other device descriptors will be added in
upcoming PRs.

Design Document for RHI:
[1] https://gerrit.openbmc.org/c/openbmc/docs/+/79327

Redfish Host Interface specification:
[2] https://www.dmtf.org/sites/default/files/standards/documents/DSP0270_1.3.0.pdf

Tested:
Tested on gb200nvl-obmc platform:
root@gb200nvl-obmc:~# ipmitool raw 0x3c 0x35
 01 bb

Change-Id: I38adf96e54350124886f46d58f0bb7490981e389
Signed-off-by: Prithvi Pai <ppai@nvidia.com>
diff --git a/oem/nvidia/bootstrap-credentials-oem-cmds.cpp b/oem/nvidia/bootstrap-credentials-oem-cmds.cpp
index b7d1bec..8b4cbdb 100644
--- a/oem/nvidia/bootstrap-credentials-oem-cmds.cpp
+++ b/oem/nvidia/bootstrap-credentials-oem-cmds.cpp
@@ -183,6 +183,12 @@
     return ipmi::responseSuccess(resBuf);
 }
 
+ipmi::RspType<uint16_t> ipmiGetRedfishServicePort()
+{
+    constexpr uint16_t redfishPort = 443;
+    return ipmi::responseSuccess(htons(redfishPort));
+}
+
 } // namespace ipmi
 
 void registerBootstrapCredentialsOemCommands()
@@ -211,4 +217,9 @@
         ipmi::prioOemBase, ipmi::groupNvidia,
         ipmi::bootstrap_credentials_oem::cmdGetRedfishServiceUUID,
         ipmi::Privilege::Admin, ipmi::ipmiGetRedfishServiceUUID);
+
+    ipmi::registerHandler(
+        ipmi::prioOemBase, ipmi::groupNvidia,
+        ipmi::bootstrap_credentials_oem::cmdGetRedfishServicePort,
+        ipmi::Privilege::Admin, ipmi::ipmiGetRedfishServicePort);
 }
diff --git a/oem/nvidia/oemcommands.hpp b/oem/nvidia/oemcommands.hpp
index 064a87e..5275e23 100644
--- a/oem/nvidia/oemcommands.hpp
+++ b/oem/nvidia/oemcommands.hpp
@@ -20,6 +20,7 @@
 constexpr auto cmdGetRedfishHostName = 0x32;
 constexpr auto cmdGetIpmiChannelRfHi = 0x33;
 constexpr auto cmdGetRedfishServiceUUID = 0x34;
+constexpr auto cmdGetRedfishServicePort = 0x35;
 } // namespace bootstrap_credentials_oem
 
 namespace bios_password