staging: fbtft: fix allyesconfig build

There are two functions call reset() so the allyesconfig breaks.  Let's
make this one static.

Reported-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Tested-by: Jim Davis <jim.epost@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>