Query the supported rate ranges from rate plugins

Query the supported rate ranges from rate plugins

Extend the PCM-rate plugin protocol to allow the host to query the
supported sample rates.  The protocol version is bumped to 0x010002,
and the version number negotiaion is slightly changed.
Now the plugin is supposed to fill the version it supports in return.

The old versioned plugins are still supported, but they may spew
version-mismatch warning prints.

Signed-off-by: Takashi Iwai <tiwai@suse.de>