[MIPS] Add Support for Additional MIPS ARCH

Doubled the numnber of .config variables modified by the Makefile.
Thanks to Brendan Kirby for his help on the sed overuse of the '|' token.

Signed-off-by: Pete Delaney <piet@mips.com>
[MIPS][X86] Updated to build X86 and to build MIPS correctly.

1. Added patches to check for system call numbers in busy box lib:

   A. Currently needed for:
      i)  X86
      ii) MIPS when compiled with -D_MIPS_SIM= which is correct.

   B. Sorry about the white space at the EOL; wasn't trivial to remove.
      Might be re-doing the patch in the near future.

   C. Will look into using syscall(__NR_restart_syscall:0)
      to set errno correctly.


2. Updated Makefile:

   A. Now supports ARCH X86.

   B. Builds MIPS ARCH with _MIPS_SIM_ABI32:
      i) Was building with -D_MIPS_SIM=_MIPS_SIM_NABI32 to get around
         a problem with system call numbers not being defined for ABI32.
         Likely deserves a better fix.

3. Disabled Vi use of signals:

   A. X86 librarys are missing siglongjmp() and sigsetjmp() symbols
      in android-ndk-r8b. Simply disabled for arm, x86, and mips for now.
      Expect a new NDK shortly. Not a problem for arm and mips.

Signed-off-by: Pete Delaney <piet@mips.com>
Rename submodule.
Merge remote-tracking branch 'piet-delaney/mips'
Add busybox-git.x86.
Enable to specify ARCH by the command line option.
Enable to specify the host environment by HOST.