MIPS: Lemote 2F: Add defconfig file

Add default config file for Lemote Loongson 2F family machines.  The
resulting kernel image can be shared between Fuloong 2F, Yeeloong 2F and
other Lemote Loongson 2F family machines.

If you are using an old PMON, and not using a 2f box, please add a new
command line argument in the boot.cfg.

For example, add this argument for 8.9inches notebook:

    machtype=lemote-yeeloong-2f-8.9inches

or

    machtype=8.9

More information from arch/mips/loongson/common/machtype.c.
Signed-off-by: Wu Zhangjin <wuzhangjin@gmail.com>
Cc: zhangfx@lemote.com
Cc: yanh@lemote.com 
Cc: huhb@lemote.com
Cc: Nicholas Mc Guire <hofrat@hofr.at>
Cc: Arnaud Patard <apatard@mandriva.com>
Cc: loongson-dev@googlegroups.com
Cc: linux-mips@linux-mips.org
Signed-off-by: Ralf Baechle <ralf@linux-mips.org>