dw_dmac: Replace module_init() with subsys_initcall()

In some cases users of dw_dmac are initialized before dw_dmac, and if they try
to use dw_dmac, they simply fail. So its better we register init() routine
of driver using subsys_initcall() instead of module_init(), so that dma driver
is available at the earliest possible.
Signed-off-by: NViresh Kumar <viresh.kumar@st.com>
Signed-off-by: NVinod Koul <vinod.koul@intel.com>

drivers/dma/dw_dmac.c

@@ -1455,7 +1455,7 @@ static int __init dw_init(void)
 {
 	return platform_driver_probe(&dw_driver, dw_probe);
 }
-module_init(dw_init);
+subsys_initcall(dw_init);
 
 static void __exit dw_exit(void)
 {