Input: lpc32xx_ts - fix device tree compatible string

During the device tree integration of the various LPC32xx drivers,
we agreed on using non-wildcard "compatible" strings. This change
switches lpc32xx_ts touchscreen driver to use "nxp,lpc3220-tsc".

Signed-off-by: Roland Stigge <stigge@antcom.de>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>