DMA: Split the APBH DMA init into block and channel init

This fixes the issue where mxs_dma_init() was called either twice or never,
without introducing any new init hooks.

The idea is to allow each and every device using the APBH DMA block to
configure and request only the channels it uses, instead of making it call init
for all the channels as is now.

The common DMA block init part, which only configures the block, is then called
from CPUs arch_cpu_init() call.

NOTE: This patch depends on:

	http://patchwork.ozlabs.org/patch/150957/

Signed-off-by: Marek Vasut <marex@denx.de>
Cc: Stefano Babic <sbabic@denx.de>
Cc: Wolfgang Denk <wd@denx.de>
Cc: Detlev Zundel <dzu@denx.de>
Cc: Fabio Estevam <fabio.estevam@freescale.com>
Tested-by: Fabio Estevam <fabio.estevam@freescale.com>
diff --git a/arch/arm/cpu/arm926ejs/mx28/mx28.c b/arch/arm/cpu/arm926ejs/mx28/mx28.c
index cf6d4e9..dc0338d 100644
--- a/arch/arm/cpu/arm926ejs/mx28/mx28.c
+++ b/arch/arm/cpu/arm926ejs/mx28/mx28.c
@@ -30,6 +30,7 @@
 #include <asm/errno.h>
 #include <asm/io.h>
 #include <asm/arch/clock.h>
+#include <asm/arch/dma.h>
 #include <asm/arch/gpio.h>
 #include <asm/arch/iomux.h>
 #include <asm/arch/imx-regs.h>
@@ -172,6 +173,11 @@
 	 */
 	mxs_gpio_init();
 
+#ifdef	CONFIG_APBH_DMA
+	/* Start APBH DMA */
+	mxs_dma_init();
+#endif
+
 	return 0;
 }
 #endif
diff --git a/arch/arm/include/asm/arch-mx28/dma.h b/arch/arm/include/asm/arch-mx28/dma.h
index 52747e2..4a1820b 100644
--- a/arch/arm/include/asm/arch-mx28/dma.h
+++ b/arch/arm/include/asm/arch-mx28/dma.h
@@ -140,6 +140,8 @@
 int mxs_dma_desc_append(int channel, struct mxs_dma_desc *pdesc);
 
 int mxs_dma_go(int chan);
-int mxs_dma_init(void);
+void mxs_dma_init(void);
+int mxs_dma_init_channel(int chan);
+int mxs_dma_release(int chan);
 
 #endif	/* __DMA_H__ */