x86: Move irq_init to x86_init_ops

irq_init is overridden by x86_quirks and by paravirts. Unify the whole
mess and make it an unconditional x86_init_ops function which defaults
to the standard function and can be overridden by the early platform
code.

Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
diff --git a/arch/x86/kernel/x86_init.c b/arch/x86/kernel/x86_init.c
index f2abe21..8cb5933 100644
--- a/arch/x86/kernel/x86_init.c
+++ b/arch/x86/kernel/x86_init.c
@@ -39,5 +39,6 @@
 
 	.irqs = {
 		.pre_vector_init	= init_ISA_irqs,
+		.intr_init		= native_init_IRQ,
 	},
 };