ARM: core DPM support for watchpoints

ARM: core DPM support for watchpoints

This is a NOP unless the underlying core exposes two new methods, and
neither of the two cores using this (ARM11xx, Cortex-A8) do so yet.

This patch only updates those cores so they pass a flag saying whether
or not to update breakpoint and watchpoint status before resuming; and
removing some now-needless anti-segfault code from ARM11.  Cortex-A8
didn't have that code ... yes, it segfaulted when setting watchpoints.

NOTE:  this uses a slightly different strategy for setting/clearing
breakpoints than the ARM7/ARM9/etc code uses.  It leaves them alone
unless it's *got* to change something, to speed halt/resume cycles
(including single stepping).

ALSO NOTE:  this under-delivers for Cortex-A8, where regions with size
up to 2 GBytes can be watched ... it handles watchpoints which ARM11 can
also handle (size 1/2/4 bytes).  Should get fixed later.

Signed-off-by: David Brownell <dbrownell@users.sourceforge.net>