Per discussion on TARGET_BYTE_ORDER_SELECTABLE.  This patch removes
TARGET_BYTE_ORDER_DEFAULT.

I suspect the patch also fixes a bug in the non-multi-arch code (Daniel
J's prodding made me revisit it).  Unlike the multi-arch case,
the non-multi-arch code wasn't updating target_byte_order with the
byte-order determined from BFD.

I'll leave this one for a few days.

Andrew

PS, the arm still comes up little endian:

ac131313@nettle$ ./gdb/gdb
GNU gdb 2002-01-20-cvs
(gdb) show endian
The target endianness is set automatically (currently little endian)
(gdb)