ARMv7a/Cortex-A8: report watchpoint trigger insn

Save and display the address of the instruction which triggered the
watchpoint.  Because of pipelining, that's well behind the PC value
when debug entry completes.  (Example in a subroutine that had been
returned from...)

Remove unused A8 stuff, mostly watchpoint hooks from the header.

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

src/target/armv7a.c

@@ -113,6 +113,9 @@ int armv7a_arch_state(struct target *target)
 
 	if (armv4_5->core_mode == ARMV4_5_MODE_ABT)
 		armv7a_show_fault_registers(target);
+	else if (target->debug_reason == DBG_REASON_WATCHPOINT)
+		LOG_USER("Watchpoint triggered at PC %#08x",
+				(unsigned) armv7a->dpm.wp_pc);
 
 	return ERROR_OK;
 }