misc: update ignored files

The place where toolchains were built has moved
from targets/ to .build/

We still ignore the old target/ dir, as users may have
samples that still use that location.

Also, reorder the ignore paterns.

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

 # m68k specific configuration file

 # depends on EXPERIMENTAL

 config ARCH_m68k

     select ARCH_SUPPORTS_32

     select ARCH_DEFAULT_32

     select ARCH_DEFAULT_BE

     select ARCH_SUPPORT_CPU

      help

       The m68k architecture