We are now strong with ppsi, remove any reference to ptp-noposix.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

We don't need a ppsi_defconfig any more, as it is now the default.
Also, use a full defconfig, so it's explicit what the options are.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

This also adds the default configuration file for ppsi.  It has no
effect, because it's the default that would apply if no configuration
file is there, but it's useful as a reference, and to ease editing.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

The PPSi daemon can now be selected in Kconfig. This commit
changes configuration and the build scripts to support either of them.

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

Both the buildroot and busybox config files are not hosted in
configs/buildroot/ within wr-switch-sw, where I expect to place
several such configuration files, at least to try different setups.

The name of the buildroot configuration file is not chosen using
Kconfig (but the default is silently applied.  If the user
provides a relative pathname, it is expanded to
wr-switch-sw/configs/buildroot .

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>

The Makefile was empty, this only adds the kconfig rules
and a default target that make silentoldconfig

Signed-off-by: Alessandro Rubini <rubini@gnudd.com>