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-i386/cpu.c b/target-i386/cpu.c
index b57ea4b..cd350cb 100644
--- a/target-i386/cpu.c
+++ b/target-i386/cpu.c
@@ -2542,12 +2542,13 @@
     cc->get_paging_enabled = x86_cpu_get_paging_enabled;
 #ifndef CONFIG_USER_ONLY
     cc->get_memory_mapping = x86_cpu_get_memory_mapping;
+    cc->get_phys_page_debug = x86_cpu_get_phys_page_debug;
     cc->write_elf64_note = x86_cpu_write_elf64_note;
     cc->write_elf64_qemunote = x86_cpu_write_elf64_qemunote;
     cc->write_elf32_note = x86_cpu_write_elf32_note;
     cc->write_elf32_qemunote = x86_cpu_write_elf32_qemunote;
+    cc->vmsd = &vmstate_x86_cpu;
 #endif
-    cpu_class_set_vmsd(cc, &vmstate_x86_cpu);
 }
 
 static const TypeInfo x86_cpu_type_info = {