configure: Use generic CXX compiler macro
configure: Use generic CXX compiler macro

This uses the AX_CXX_COMPILE_STDCXX() instead of
AX_CXX_COMPILE_STDCXX_1{4,7}() so that the error messages we generate
make slightly more sense.

We get errors like:
configure.ac:24: error: invalid first argument `20' to
AX_CXX_COMPILE_STDCXX

Instead of:
./configure: line 5132: syntax error near unexpected token `noext'
./configure: line 5132: `AX_CXX_COMPILE_STDCXX_20(noext)'

Change-Id: I05512c977b8b3215a02b5d4dc6dba30ac2b83728
Signed-off-by: William A. Kennington III <30fff5198f4d10ca1117e5f3ec82f3b4b8900d81@google.com>

openbmc/phosphor-host-ipmid,openbmc/phosphor-host-ipmid,openbmc/phosphor-host-ipmid