Remove legacy SSP API by deprecating the only user now - corgi_ts.c, (which could be now well substituted by ads7846 after the sync patch)

sound/soc/pxa/pxa-ssp.c is modified and simplified a bit.

I guess sound/soc/pxa/pxa-ssp.c will still have to undergo the changes as ASoCv2 progress, hopefully that should be a little bit easier now.