DMAENGINE: move COH901318 to arch_initcall

After moving the PL022 driver to subsys_initcall() due to the need
of having stuff like regulators on the other end of the SPI link,
I noticed that the COH901318 DMA engine will get probed before
the DMA engine, so move it to an arch_initcall().

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dma/coh901318.c b/drivers/dma/coh901318.c
index 557e227..f79fc26 100644
--- a/drivers/dma/coh901318.c
+++ b/drivers/dma/coh901318.c
@@ -1609,7 +1609,7 @@
 {
 	return platform_driver_probe(&coh901318_driver, coh901318_probe);
 }
-subsys_initcall(coh901318_init);
+arch_initcall(coh901318_init);
 
 void __exit coh901318_exit(void)
 {