With the patch 
7230c564 (powerpc: Rework lazy-interrupt handling),
it seems that the coreint works pretty well on the 85xx 64bit kernel.
So use the coreint by default for these boards.
Signed-off-by: Kevin Hao <haokexin@gmail.com>
Signed-off-by: Scott Wood <scottwood@freescale.com>
 
 #ifdef CONFIG_PCI
        .pcibios_fixup_bus      = fsl_pcibios_fixup_bus,
 #endif
-/* coreint doesn't play nice with lazy EE, use legacy mpic for now */
-#ifdef CONFIG_PPC64
-       .get_irq                = mpic_get_irq,
-#else
        .get_irq                = mpic_get_coreint_irq,
-#endif
        .restart                = fsl_rstcr_restart,
        .calibrate_decr         = generic_calibrate_decr,
        .progress               = udbg_progress,
 
 #ifdef CONFIG_PCI
        .pcibios_fixup_bus      = fsl_pcibios_fixup_bus,
 #endif
-/* coreint doesn't play nice with lazy EE, use legacy mpic for now */
-#ifdef CONFIG_PPC64
-       .get_irq                = mpic_get_irq,
-#else
        .get_irq                = mpic_get_coreint_irq,
-#endif
        .restart                = fsl_rstcr_restart,
        .calibrate_decr         = generic_calibrate_decr,
        .progress               = udbg_progress,
 
 #ifdef CONFIG_PCI
        .pcibios_fixup_bus      = fsl_pcibios_fixup_bus,
 #endif
-/* coreint doesn't play nice with lazy EE, use legacy mpic for now */
-#ifdef CONFIG_PPC64
-       .get_irq                = mpic_get_irq,
-#else
        .get_irq                = mpic_get_coreint_irq,
-#endif
        .restart                = fsl_rstcr_restart,
        .calibrate_decr         = generic_calibrate_decr,
        .progress               = udbg_progress,