Input: cypress_ps2 - do not consider data bad if palm is detected

If hardware (or firmware) detects palm on the surface of the device it does
not mean that the data packet is bad from the protocol standpoint. Instead
of reporting PSMOUSE_BAD_DATA in this case simply threat it as if nothing
touches the surface.

BugLink: http://bugs.launchpad.net/bugs/1229361
Signed-off-by: Joseph Salisbury <joseph.salisbury@canonical.com>
Tested-by: Kamal Mostafa <kamal@canonical.com>
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>