Fix compiler/assembler flags for Ebony platform boot files

[Josh Boyer]

On Fri, 2007-05-25 at 13:19 +1000, David Gibson wrote:
> The recent addition of assembler flags for 44x.c and ebony.c in the
> bootwrapper to make them compile on certain toolchains was not correct
> and could break other platforms.  This patch switches to using a
> compiler flag instead, which implies the appropriate assembler flag,
> and also stops the compiler itself generating instructions which are
> invalid for the platform in question.

This looks good to me, but I don't have one of the failing toolchains.
Dave, can you test this patch out?

josh