Pull ARC fixes from Vineet Gupta:
 "Here's a late pull request for accumulated ARC fixes which came out of
  extended testing of the new ARCv2 port with LTP etc.  llock/scond
  livelock workaround has been reviewed by PeterZ.  The changes look a
  lot but I've crafted them into finer grained patches for better
  tracking later.

  I have some more fixes (ARC Futex backend) ready to go but those will
  have to wait for tglx to return from vacation.

  Summary:
   - Enable a reduced config of HS38 (w/o div-rem, ll64...)
   - Add software workaround for LLOCK/SCOND livelock
   - Fallout of a recent pt_regs update"

* tag 'arc-v4.2-rc6-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/vgupta/arc:
  ARCv2: spinlock/rwlock/atomics: reduce 1 instruction in exponential backoff
  ARC: Make pt_regs regs unsigned
  ARCv2: spinlock/rwlock: Reset retry delay when starting a new spin-wait cycle
  ARCv2: spinlock/rwlock/atomics: Delayed retry of failed SCOND with exponential backoff
  ARC: LLOCK/SCOND based rwlock
  ARC: LLOCK/SCOND based spin_lock
  ARC: refactor atomic inline asm operands with symbolic names
  Revert "ARCv2: STAR 9000837815 workaround hardware exclusive transactions livelock"
  ARCv2: [axs103_smp] Reduce clk for Quad FPGA configs
  ARCv2: Fix the peripheral address space detection
  ARCv2: allow selection of page size for MMUv4
  ARCv2: lib: memset: Don't assume 64-bit load/stores
  ARCv2: lib: memcpy: Missing PREFETCHW
  ARCv2: add knob for DIV_REV in Kconfig
  ARC/time: Migrate to new 'set-state' interface