[yocto] [yocto-docs][PATH] Emphasize both 32- and 64-bit MIPS supported.

[Khem Raj]

On Wed, Jul 30, 2014 at 12:32 PM, Robert P. J. Day
<rpjday at crashcourse.ca> wrote:
> -        on ARM, MIPS, PowerPC, x86 and x86-64.
> +        on ARM, MIPS (both 32- and 64-bit), PowerPC, x86 and x86-64.

we usually use MIPS to denote 32bit and then MIPS64 to denote 64bit mips.