[PATCH] drm: xlnx: fix build warning & errors when DMADEVICES is not set

[Randy Dunlap]

From: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>

Fix kconfig warnings & build errors caused by DRM_ZYNQMP_DPSUB.

Any driver that selects DMA_ENGINE should make sure that
DMADEVICES is already enabled.
As is, this causes build errors in many other drivers.

See https://lore.kernel.org/lkml/202009020239.oUPh82Xc%25lkp@xxxxxxxxx/
for the numerous build errors.

WARNING: unmet direct dependencies detected for DMA_ENGINE
  Depends on [n]: DMADEVICES [=n]
  Selected by [y]:
  - DRM_ZYNQMP_DPSUB [=y] && HAS_IOMEM [=y] && (ARCH_ZYNQMP || COMPILE_TEST [=y]) && COMMON_CLK [=y] && DRM [=y] && OF [=y]

Reported-by: kernel test robot <lkp@xxxxxxxxx>
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Hyun Kwon <hyun.kwon@xxxxxxxxxx>
Cc: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
---
 drivers/gpu/drm/xlnx/Kconfig |    1 +
 1 file changed, 1 insertion(+)

--- linux-next-20200903.orig/drivers/gpu/drm/xlnx/Kconfig
+++ linux-next-20200903/drivers/gpu/drm/xlnx/Kconfig
@@ -2,6 +2,7 @@ config DRM_ZYNQMP_DPSUB
 	tristate "ZynqMP DisplayPort Controller Driver"
 	depends on ARCH_ZYNQMP || COMPILE_TEST
 	depends on COMMON_CLK && DRM && OF
+	depends on DMADEVICES
 	select DMA_ENGINE
 	select DRM_GEM_CMA_HELPER
 	select DRM_KMS_CMA_HELPER