[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>

arch/arm/mach-footbridge/dma.c

@@ -41,7 +41,7 @@ static struct dma_ops fb_dma_ops = {
 };
 #endif
 
-void __init arch_dma_init(dma_t *dma)
+static int __init fb_dma_init(void)
 {
 #if 0
 	dma[_DC21285_DMA(0)].d_ops = &fb_dma_ops;
@@ -49,6 +49,8 @@ void __init arch_dma_init(dma_t *dma)
 #endif
 #ifdef CONFIG_ISA_DMA
 	if (footbridge_cfn_mode())
-		isa_init_dma(dma + _ISA_DMA(0));
+		isa_init_dma();
 #endif
+	return 0;
 }
+core_initcall(fb_dma_init);