Add system interface as the channel for the legacy interface

The legacy interface org.openbmc.HostIpmi is used by the btbridge
interface and the channel number was set to 0 which implies the IPMB
bridge. This is corrected to use the system interface.

Change-Id: I870d8fc6c2461b7fc75a90f9576f08599038f211
Signed-off-by: Tom Joseph <tomjoseph@in.ibm.com>
diff --git a/ipmid-new.cpp b/ipmid-new.cpp
index c32ba3f..823b9d8 100644
--- a/ipmid-new.cpp
+++ b/ipmid-new.cpp
@@ -750,7 +750,8 @@
         m.read(seq, netFn, lun, cmd, data);
         std::shared_ptr<sdbusplus::asio::connection> bus = getSdBus();
         auto ctx = std::make_shared<ipmi::Context>(
-            bus, netFn, cmd, 0, 0, ipmi::Privilege::Admin, 0, &yield);
+            bus, netFn, cmd, ipmi::channelSystemIface, 0,
+            ipmi::Privilege::Admin, 0, &yield);
         auto request = std::make_shared<ipmi::message::Request>(
             ctx, std::forward<std::vector<uint8_t>>(data));
         ipmi::message::Response::ptr response =