Input: uinput - handle compat ioctl for UI_SET_PHYS

When running a 32-bit userspace on a 64-bit kernel, the UI_SET_PHYS
ioctl needs to be treated with special care, as it has the pointer
size encoded in the command.

Signed-off-by: Ricky Liang <jcliang@chromium.org>
Cc: stable@vger.kernel.org
Signed-off-by: Dmitry Torokhov <dmitry.torokhov@gmail.com>