config: fix recursive deps

The latest kconfig stuff is more stringent when it comes to validating
the dependency of the symbols. It is no longer possible to have a symbol
depend on itself (such as our construct for arch/cc/libc/... was doing).

Fix our generated-file infrastructure to avoid these situations when the
new kconfig stuff will be merged (in a following changeset).

Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

 # Bare metal config options

 ## select BARE_METAL

 ##

 ## help 'Bare metal' refers to those programs that run without any kernel.

 ## help

 ## help You probably want to say 'y' here if you plan to use your compiler

 ## help to build bootloaders. It is not yet suitable to build Linux kernels,

 ## help though, because the APCI stuff relies on the target C library headers

 ## help being available?!?!...