dmaengine: inherit debug settings from the subsystem for subdirectories

To be able to see debug messages during boot, enable the debug settings
from Kconfig also for drivers in subdirectories.
Signed-off-by: Wolfram Sang <wsa+renesas@sang-engineering.com>
Signed-off-by: Vinod Koul <vinod.koul@intel.com>

drivers/dma/Makefile

-ccflags-$(CONFIG_DMADEVICES_DEBUG)  := -DDEBUG
-ccflags-$(CONFIG_DMADEVICES_VDEBUG) += -DVERBOSE_DEBUG
+subdir-ccflags-$(CONFIG_DMADEVICES_DEBUG)  := -DDEBUG
+subdir-ccflags-$(CONFIG_DMADEVICES_VDEBUG) += -DVERBOSE_DEBUG
 
 obj-$(CONFIG_DMA_ENGINE) += dmaengine.o
 obj-$(CONFIG_DMA_VIRTUAL_CHANNELS) += virt-dma.o