binutils/elf2flt: restore the custom location functionality

Somehow, it got lost when incorporating elf2flt in the binutils farmework.

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

 reporter_name="Yann Diorcet <diorcet.yann@gmail.com>"

 reporter_url=""

 reporter_comment="Config to build cross-compiler with mingw as kernel type for

 64 bits Windows target"