iommu/amd: Add slab-cache for irq remapping tables

The irq remapping tables for the AMD IOMMU need to be
aligned on a 128 byte boundary. Create a seperate slab-cache
to guarantee this alignment.

Signed-off-by: Joerg Roedel <joerg.roedel@amd.com>

drivers/iommu/irq_remapping.h

@@ -83,6 +83,11 @@ struct irq_remap_ops {
 
 extern struct irq_remap_ops intel_irq_remap_ops;
 
+#else  /* CONFIG_IRQ_REMAP */
+
+#define irq_remapping_enabled 0
+#define disable_irq_remap     1
+
 #endif /* CONFIG_IRQ_REMAP */
 
 #endif /* __IRQ_REMAPPING_H */