Config.in.legacy: fix misc. problems with libnfc-llcp removal

The Config.in.legacy entry associated with the replacement of libnfc-llcp
was broken in multiple ways:

- it was not correctly added within the section for 2014.02 deprecation
  (recently fixed by Yann E. Morin with commit
  f169e5e1)
- it still had select/depend statements from the original symbol, which
  should not be added in Config.in.legacy.
- it did not select the replacement symbol as to make the transition for
  users more convenient.
- indentation of the help text was not tab+2spaces.

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>