Pull ARC updates from Vineet Gupta:

 - perf fixes/improvements

 - misc cleanups

* tag 'arc-4.1-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARC: perf: don't add code for impossible case
  ARC: perf: Rename DT binding to not confuse with power mgmt
  ARC: perf: add user space attribution in callchains
  ARC: perf: Add kernel callchain support
  ARC: perf: support cache hit/miss ratio
  ARC: perf: Add some comments/debug stuff
  ARC: perf: make @arc_pmu static global
  ARC: mem init spring cleaning - No functional changes
  ARC: Fix RTT boot printing
  ARC: fold __builtin_constant_p() into test_bit()
  ARC: rename unhandled exception handler
  ARC: cosmetic: Remove unused ECR bitfield masks
  ARC: Fix WRITE_BCR
  ARC: [nsimosci] Update defconfig
  arc: copy_thread(): rename 'arg' argument to 'kthread_arg'