We now have CONFIG_USE_HA that selects the ha ppsi
configuration. Please make sure to remove ppsi/.config, as Makefile
makes the right choice if missing but won't overwrite it (otherwise,
we couldn't check different ppsi configs during development).

We force CMD_CONFIG on, so in case of doubts you can issue "config"
to check USE_HA/USE_WR. if there is no "config" command it's
WR for sure.
Signed-off-by: Alessandro Rubini <rubini@gnudd.com>