Staging: fbtft: Remove paragraph about writing to FSF

Remove paragraph about writing to the Free Software Foundation's
mailing address from GPL notice.
This patch fixes the following checkpatch error:

CHECK:FSF_MAILING_ADDRESS at line 17.

Signed-off-by: Fabio Falzoi <fabio.falzoi84@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>