package/lua: rename config options

Package's options should be named after the package.

Lua is an interpreter, but the package is named 'lua'. So we want to
name the config option with '_LUA_', not with '_LUA_INTERPRETER_'

Besides, naming them with '_LUA_INTERPRETER_' might be confusing, since
there is a package named 'luainterpreter'.

Since the renamed options are part of a choice, we can't use the legacy
options to select the new ones. So we instead instruct the user to go
select the appropriate option in the choice.

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@free.fr>
Cc: Francois Perrad <fperrad@gmail.com>
Reviewed-by: Samuel Martin <s.martin49@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>