Config i386 build i386ex expects i386-gcc compiler

[John Jeffers]

Just as a minor bug:

On a clean install of rtems-4.5.0.beta3a the config script calls out 
i386-gcc just before going to create makefiles (during the checking for gcc 
and that it is a cross compiler).

Build fails.

Copying i386-rtems-gcc to i386-gcc fixed the issue which leads me to 
believe that during testing typically there was a i386-gcc cross compiler 
in the PATH.

Config should call out the gcc found in the RH Linux pre-prepared RPM.

Cheers John