This does two things:

 (1) Move the v850 platform-specific linker-script fragments into
     arch/v850/kernel, from arch/v850.  This move was prompted by a
     recent (all-architecture) move for vmlinux.lds.S, to keep the
     script together, but I think it also makes sense -- this way, all
     platform-specific non-header files are in the same directory with
     similar names.

 (2) Remove some hardwired constants in the linker script fragments,
     using already defined cpp macros anyway.  This eliminates one
     annoying source of duplicate definitions (which had to be kept in
     sync).