binutils: allow choice for elf format when building bare-metal cross compiler

When building a baremetal cross compiler I want to be able to select
the elf format and not be forced to build the elf2flt package.

Signed-off-by: Bart vdr. Meulen <bartvdrmeulen@gmail.com>
[Yann E. MORIN: tweak the commit message]
Signed-off-by: "Yann E. MORIN" <yann.morin.1998@anciens.enib.fr>

     1.1 --- a/config/binutils.in	Fri Apr 09 21:04:27 2010 +0200
     1.2 +++ b/config/binutils.in	Fri Apr 09 21:04:28 2010 +0200
     1.3 @@ -6,7 +6,7 @@
     1.4      bool
     1.5      prompt "Binary format:"
     1.6  
     1.7 -if ARCH_USE_MMU
     1.8 +if ARCH_USE_MMU || BARE_METAL
     1.9  
    1.10  config ARCH_BINFMT_ELF
    1.11      bool