superio/ite: Use common dispatch for pnp entry/exit functions

We already have these implemented under superio/common, use
those instead of this copy-paste syndrom.

Change-Id: I7c7737e0b3c284d8b14b36c70681ab2269bb1d4b
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/7310
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
mainboard/dmp/vortex86ec: Unused variable in romstage.c

Change-Id: I9cc549b7862ee535928bd06b5fb4bd38bb67a992
Signed-off-by: Edward O'Callaghan <eocallaghan@alterapraxis.com>
Reviewed-on: http://review.coreboot.org/7279
Tested-by: build bot (Jenkins)
Reviewed-by: Kyösti Mälkki <kyosti.malkki@gmail.com>