x86, apic: untangle the send_IPI_*() jungle

Our send_IPI_*() methods and definitions are a twisted mess: the same
symbol is defined to different things depending on .config details,
in a non-transparent way.

 - spread out the quirks into separately named per apic driver methods

 - prefix the standard PC methods with default_

 - get rid of wrapper macro obfuscation

 - clean up various details

Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/arch/x86/include/asm/hw_irq.h b/arch/x86/include/asm/hw_irq.h
index 8de644b6..bfa921f 100644
--- a/arch/x86/include/asm/hw_irq.h
+++ b/arch/x86/include/asm/hw_irq.h
@@ -73,9 +73,9 @@
 
 /* IPI functions */
 #ifdef CONFIG_X86_32
-extern void send_IPI_self(int vector);
+extern void default_send_IPI_self(int vector);
 #endif
-extern void send_IPI(int dest, int vector);
+extern void default_send_IPI(int dest, int vector);
 
 /* Statistics */
 extern atomic_t irq_err_count;