[U-Boot] MIPS: tb0229 build error caused by <asm/ppc4xx.h> reference

[Shinya Kuribayashi]

Hi Komiya-san,

Since the commit below, tb0229 target has been broken for months because
<ppc4xx.h> and <ppc405.h> can not be easily included as used to by MIPS
ports any more.

> commit b36df561154bdd0a41bb77e09c5575ca2cf48013
> Author: Stefan Roese <sr at denx.de>
> Date:   Thu Sep 9 19:18:00 2010 +0200
> 
>     ppc4xx: Move ppc4xx headers to powerpc include directory
>     
>     This patch moves some ppc4xx related headers from the common include
>     directory (include/) to the powerpc specific one
>     (arch/powerpc/include/asm/). This way to common include directory is not
>     so cluttered with files.
>     
>     Signed-off-by: Stefan Roese <sr at denx.de>

$ ./MAKEALL tb0229
[...]
flash.c:27: fatal error: asm/ppc4xx.h: No such file or directory
make[1]: *** [flash.o] Error 1

I can not come up with a reasonble workaround at this moment.  Could you
take a look please?  And let us know what we do next, thanks.