linux-yocto/3.4: add qemumipsel machine mapping

linux-yocto/3.4: add qemumipsel machine mapping

Updating the meta branch with a board description and configuration
that can be found from the linux-yocto recipes without doing a
MACHINE -> KMACHINE mapping.

From the meta branch commit:

    The mti malta board description for a little endian config can't
    be found by default unless it has a matching KMACHINE, or the
    KMACHINE is set in a kernel recipe. In this case, it is easier to
    just add qemumipsel in the KMACHINE list, so the recipe doesn't
    need to do the mapping.

The little endian mips support reuses everything but the endianess
settings from the big endian mti malta board emulation.

This change adds the required mappings and SRCREVs, but does not
update the machine compatibilty, since official support is still
pending. The compatibility can be set in addon layers until that
time.

(From OE-Core rev: de2535b2bb47b80bdaeb3053b0ac0d1bbb9c5d53)

Signed-off-by: Bruce Ashfield <bruce.ashfield@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>