Merge tag 'xtensa-for-next-20140815' into for_next

Xtensa improvements for 3.17:
- support highmem on cores with aliasing data cache. Enable highmem on kc705
  by default;
- simplify addition of new core variants (no need to modify Kconfig /
  Makefiles);
- improve robustness of unaligned access handler and its interaction with
  window overflow/underflow exception handlers;
- deprecate atomic and spill registers syscalls;
- clean up Kconfig: remove orphan MATH_EMULATION, sort 'select' statements;
- wire up renameat2 syscall.

Various fixes:
- fix address checks in dma_{alloc,free}_coherent (runtime BUG);
- fix access to THREAD_RA/THREAD_SP/THREAD_DS (debug build breakage);
- fix TLBTEMP_BASE_2 region handling in fast_second_level_miss (runtime
  unrecoverable exception);
- fix a6 and a7 handling in fast_syscall_xtensa (runtime userspace register
  clobbering);
- fix kernel/user jump out of fast_unaligned (potential runtime unrecoverable
  exception);
- replace termios IOCTL code definitions with constants (userspace build
  breakage).

Signed-off-by: Chris Zankel <chris@zankel.net>