CHROMEOS: HID: logitech-dj: move .h file info .c file.

CHROMEOS: HID: logitech-dj: move .h file info .c file.

This is part of the next iteration of Nestor Lopez Casado's
introduction of HID++ support to the kernel from his patch "[PATCH
1/1] HID: Add full MT support for Logitech Wireless Touchpad"

These definitions are only used by the .c file.

BUG=chromium-os:39354
TEST=manually tested on Link

Signed-off-by: Andrew de los Reyes <adlr@chromium.org>
Change-Id: Ie745aad4dd782214725c0930ec3b82feed5554cd
Reviewed-on: https://gerrit.chromium.org/gerrit/46008
Reviewed-by: Yufeng Shen <miletus@chromium.org>