dmaengine: sirf: move driver init from module_init to subsys_initcall

if we initilize dma driver by module_init, there are still many devices
which will be initilized earlier than dma. these devices will fail to
get dma channel.
this moves dmaengine earlier than device_initcall and make dma available
for all devices.
Reported-by: Renwei Wu <Renwei.Wu@csr.com>
Signed-off-by: Barry Song <Baohua.Song@csr.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/sirf-dma.c

@@ -753,7 +753,18 @@ static struct platform_driver sirfsoc_dma_driver = {
 	},
 };
 
-module_platform_driver(sirfsoc_dma_driver);
+static __init int sirfsoc_dma_init(void)
+{
+	return platform_driver_register(&sirfsoc_dma_driver);
+}
+
+static void __exit sirfsoc_dma_exit(void)
+{
+	platform_driver_unregister(&sirfsoc_dma_driver);
+}
+
+subsys_initcall(sirfsoc_dma_init);
+module_exit(sirfsoc_dma_exit);
 
 MODULE_AUTHOR("Rongjun Ying <rongjun.ying@csr.com>, "
 	"Barry Song <baohua.song@csr.com>");