defconfig: make new defconfig for diverging from upstream; unique version id

arch/arm/configs/s87cm_d2_defconfig: new defconfig to hold any divergent
changes I make from the upstream defconfigs. Helps avoid merge conflicts,
at the expense of having to migrate defconfig changes manually. Also,
added a custom version identifier string; was '-cyanogenmod', now
'-s87cm-kk'
defconfig: remove NETFILTER_ADVANCED declaration from main defconfig

s87cm_d2_defconfig: the NETFILTER_ADVANCED symbol has been moved so
it is now defined in m2selinux_defconfig, but the declaration was
not removed from the main defconfig. This causes a warning during
configuration as the Kconfig system has to deal with the duplicate
definitions. This is completely harmless, other than the warning. I
guess I'm just a little OCD. :D
defconfig: defconfig updates; disable arm unwinding

Bring in missing symbol defines; not sure why they weren't in there
to begin with, but they are now. Also disabled arm unwinding. It
causes a lot of errors when linking everything together, and based
on those warnings, I would guess that unwinding doesn't work anyway,
since the proper symbols are not included in the proper stacks.