Reading SOL non-volatile bitrate broken for VUART

[Oskar Senft]

Hi everyone

After syncing phosphor-host-ipmid to
a48bf7766f7e2f9cbe1c74f3ee681f7a2ea66969
(https://github.com/openbmc/phosphor-host-ipmid/commit/a48bf7766f7e2f9cbe1c74f3ee681f7a2ea66969)
I found that `ipmitool sol info 1` no longer works. I tracked it down
to obmc-consoler-server not exposing interface
xyz.openbmc_project.Console.UART for VUART type ports.

I believe obmc-consoler-server's behavior is correct, since there's no
baud rate for VUART ports to configure.

I worked around by having getSolConfParams return
`response(ccParamNotSupported)` rather than
`ipmi::responseUnspecifiedError()` in the case where
`ipmi::getDbusProperty` fails for the Baud property.

diff --git a/transporthandler.cpp b/transporthandler.cpp
index f89f8f3..a7b565a 100644
--- a/transporthandler.cpp
+++ b/transporthandler.cpp
@@ -1682,7 +1682,7 @@ RspType<message::Payload>
getSolConfParams(Context::ptr ctx,
                     "/xyz/openbmc_project/console/default",
                     "xyz.openbmc_project.Console.UART", "Baud", baudRate))
             {
-                return ipmi::responseUnspecifiedError();
+                return response(ccParamNotSupported);
             }
             switch (baudRate)
             {

With that change the behavior reverts to what it was prior to the commit.

Thoughts?

Thanks
Oskar.