[ARM] dma: rejig DMA initialization

Rather than having the central DMA multiplexer call the architecture
specific DMA initialization function, have each architecture DMA
initialization function use core_initcall(), and register each DMA
channel separately with the multiplexer.

This removes the array of dma structures in the central multiplexer,
replacing it with an array of pointers instead; this is more flexible
since it allows the drivers to wrap the DMA structure (eventually
allowing us to transition non-ISA DMA drivers away.)

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/include/asm/mach/dma.h b/arch/arm/include/asm/mach/dma.h
index 281ae7e..38a3693 100644
--- a/arch/arm/include/asm/mach/dma.h
+++ b/arch/arm/include/asm/mach/dma.h
@@ -48,10 +48,12 @@
 	struct dma_ops	*d_ops;
 };
 
-/* Prototype: void arch_dma_init(dma)
- * Purpose  : Initialise architecture specific DMA
- * Params   : dma - pointer to array of DMA structures
+/*
+ * isa_dma_add - add an ISA-style DMA channel
  */
-extern void arch_dma_init(dma_t *dma);
+extern int isa_dma_add(unsigned int, dma_t *dma);
 
-extern void isa_init_dma(dma_t *dma);
+/*
+ * Add the ISA DMA controller.  Always takes channels 0-7.
+ */
+extern void isa_init_dma(void);