Also hide shim code added in a previous commit under COMPAT_USBHID12.
Note: it is enough to add -DCOMPAT_USBHID12 to CFLAGS to compile old
code with new HID subsystem, but it is not enough to link it at runtime.
HID dependency has to be added explicitly with MODULE_DEPEND macro.
Reviewed by: manu, hselasky (as part of D27887)
eead9017d2