If invocations are hidden behind config guards the count of how
many invocations there are will be wrong. The C compiler will
correctly assign the value with enum auto numbering, so there's
no need to override that here
Placing a config condition on the first define
in sel4arch.xml will fail as currently the first define
must start at the last define + 1 of the previous
invocation enum.
If this is ever required, autoconf.h will need to be passed
to the script so it can check config variables itself.
