x86: refactor x86_quirks support

Impact: cleanup

Make x86_quirks support more transparent. The highlevel
methods are now named:

  extern void x86_quirk_pre_intr_init(void);
  extern void x86_quirk_intr_init(void);

  extern void x86_quirk_trap_init(void);

  extern void x86_quirk_pre_time_init(void);
  extern void x86_quirk_time_init(void);

This makes it clear that if some platform extension has to
do something here that it is considered ... weird, and is
discouraged.

Also remove arch_hooks.h and move it into setup.h (and other
header files where appropriate).

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/i8259.h b/arch/x86/include/asm/i8259.h
index 58d7091..1a99e6c 100644
--- a/arch/x86/include/asm/i8259.h
+++ b/arch/x86/include/asm/i8259.h
@@ -60,4 +60,8 @@
 extern void mask_8259A(void);
 extern void unmask_8259A(void);
 
+#ifdef CONFIG_X86_32
+extern void init_ISA_irqs(void);
+#endif
+
 #endif /* _ASM_X86_I8259_H */