Revert "HID: Add input_register callback."

This reverts commit f4768a7d.

This patch updated one of the callbacks (input_configured)
but didn't update the respective drivers, so we end up running
into a lot of warnings when building HID drivers. e.g.

drivers/hid/hid-sony.c:2160:2: warning: initialization from
incompatible pointer type [enabled by default]
  .input_configured = sony_input_configured,
  ^
...and so on.

Hence revert this patch and cherry-pick the upstream(4.4-rc1)
commit 9154301a "HID: hid-input: allow input_configured
callback return errors" instead.

Signed-off-by: Amit Pundir <amit.pundir@linaro.org>