Debugging options for the DMA engine subsystem

This adds Kconfig options for DEBUG and VERBOSE_DEBUG to the DMA
engine subsystem, I got tired of editing the Makefile manually
each time I want to debug things in here, modelled this on the
debug switches for other subsystems and works like a charm when
working on our DMA engines.

Signed-off-by: Linus Walleij <linus.walleij@stericsson.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
diff --git a/drivers/dma/Makefile b/drivers/dma/Makefile
index 807053d..54112d6 100644
--- a/drivers/dma/Makefile
+++ b/drivers/dma/Makefile
@@ -1,3 +1,10 @@
+ifeq ($(CONFIG_DMADEVICES_DEBUG),y)
+	EXTRA_CFLAGS	+= -DDEBUG
+endif
+ifeq ($(CONFIG_DMADEVICES_VDEBUG),y)
+	EXTRA_CFLAGS	+= -DVERBOSE_DEBUG
+endif
+
 obj-$(CONFIG_DMA_ENGINE) += dmaengine.o
 obj-$(CONFIG_NET_DMA) += iovlock.o
 obj-$(CONFIG_DMATEST) += dmatest.o