MIPS: generic: Bump default NR_CPUS to 16

In generic_defconfig set CONFIG_NR_CPUS to 16 rather than 2, which is a
rather too low limit for many modern day MIPS systems.

Signed-off-by: Paul Burton <paul.burton@imgtec.com>
Cc: linux-mips@linux-mips.org
Patchwork: https://patchwork.linux-mips.org/patch/16949/


Signed-off-by: Ralf Baechle <ralf@linux-mips.org>