* Define NO_ACTION_MACRO/FUNCTION in header instead of makefile when LTO is enabled
Currently, boards and keymaps that define NO_ACTION_MACRO/FUNCTION unconditionally
will not compile with LTO_ENABLE (#8604). This fixes the issue by moving the
definitions from common.mk to action.h, which enables us to check for previous
definitions of those macros (this cannot be done in a makefile).
* Remove LTO checks in templates
Since now NO_ACTION_MACRO/FUNCTION are defined as needed in action.h (which is
included by quantum.h), checking for LTO in keyboard and user code is no
longer required.
* Update LTO_ENABLE docs
be2f5816b6