Input: joydev - decouple axis and button map ioctls from input constants

The KEY_MAX change in 2.6.28 changed the values of the JSIOCSBTNMAP and
JSIOCGBTNMAP constants; software compiled with the old values no longer
works with kernels following 2.6.28, because the ioctl switch statement
no longer matches the values given by the software. This patch handles
these ioctls independently of the length of data specified, and applies the
same treatment to JSIOCSAXMAP and JSIOCGAXMAP which currently depend on
ABS_MAX.

Signed-off-by: Stephen Kitt <steve@sk2.org>
Signed-off-by: Dmitry Torokhov <dtor@mail.ru>