Add slot ipmb command

Added slot ipmb command which is used to send commands to add-in cards.
BMC will act as a bridge and forwards the data to the add-in card and
returns the response from the add-in card.

Tested:

ipmitool raw 0x3e 0x51 <address_type> <slot_num> <slave_addr> <net_fun>
<cmd>
00 //success

ipmitool raw 0x3e 0x51 <address_type> <invalid_slot_num> <slave_addr>
<net_fun> <cmd>
0xce //Command response could not be provided

ipmitool raw 0x3e 0x51 <address_type> <slot_num> <invalid_slave_addr>
<net_fun> <cmd>
0xce //Command response could not be provided

Tested the command from the shell using cmdtool via KCS interface and it
works fine.

Signed-off-by: Rajashekar Gade Reddy <raja.sekhar.reddy.gade@linux.intel.com>
Change-Id: Ic772e169569ee91328315a02633089d3894e1b0f
diff --git a/include/oemcommands.hpp b/include/oemcommands.hpp
index 7a8e445..13586c5 100644
--- a/include/oemcommands.hpp
+++ b/include/oemcommands.hpp
@@ -106,6 +106,7 @@
 static constexpr Cmd cmdMdrIIDataStart = 0x3b;
 static constexpr Cmd cmdMdrIIDataDone = 0x3c;
 static constexpr Cmd cmdMdrIISendDataBlock = 0x3d;
+static constexpr Cmd cmdSlotIpmb = 0x51;
 } // namespace app
 
 } // namespace intel