cpu: Turn cpu_get_phys_page_debug() into a CPUClass hook

Change breakpoint_invalidate() argument to CPUState alongside.

Since all targets now assign a softmmu-only field, we can drop helpers
cpu_class_set_{do_unassigned_access,vmsd}() and device_class_set_vmsd().

Prepares for changing cpu_memory_rw_debug() argument to CPUState.

Acked-by: Max Filippov <jcmvbkbc@gmail.com> (for xtensa)
Signed-off-by: Andreas Färber <afaerber@suse.de>
diff --git a/target-alpha/cpu-qom.h b/target-alpha/cpu-qom.h
index 60125b1..b2eeba3 100644
--- a/target-alpha/cpu-qom.h
+++ b/target-alpha/cpu-qom.h
@@ -81,5 +81,6 @@
 void alpha_cpu_do_interrupt(CPUState *cpu);
 void alpha_cpu_dump_state(CPUState *cs, FILE *f, fprintf_function cpu_fprintf,
                           int flags);
+hwaddr alpha_cpu_get_phys_page_debug(CPUState *cpu, vaddr addr);
 
 #endif