[ARM] pxa: remove now un-used corgi_ssp.c and corgi_lcd.c

The only use of corgi_ssp.c is corgi_ts.c, which is now deprecated
and removed. Remove corgi_ssp.c and corgi_lcd.c and their relevant
function declarations and data structures.

Signed-off-by: Eric Miao <eric.y.miao@gmail.com>
Cc: Richard Purdie <rpurdie@rpsys.net>
Cc: Pavel Machek <pavel@ucw.cz>