[PATCH] staging: ralink-gdma: fix kconfig dependency bug for DMA_RALINK

[Necip Fazil Yildiran]

When DMA_RALINK is enabled and DMADEVICES is disabled, it results in the
following Kbuild warnings:

WARNING: unmet direct dependencies detected for DMA_ENGINE
  Depends on [n]: DMADEVICES [=n]
  Selected by [y]:
  - DMA_RALINK [=y] && STAGING [=y] && RALINK [=y] && !SOC_RT288X [=n]

WARNING: unmet direct dependencies detected for DMA_VIRTUAL_CHANNELS
  Depends on [n]: DMADEVICES [=n]
  Selected by [y]:
  - DMA_RALINK [=y] && STAGING [=y] && RALINK [=y] && !SOC_RT288X [=n]

The reason is that DMA_RALINK selects DMA_ENGINE and DMA_VIRTUAL_CHANNELS
without depending on or selecting DMADEVICES while DMA_ENGINE and
DMA_VIRTUAL_CHANNELS are subordinate to DMADEVICES. This can also fail
building the kernel as demonstrated in a bug report.

Honor the kconfig dependency to remove unmet direct dependency warnings
and avoid any potential build failures.

Link: https://bugzilla.kernel.org/show_bug.cgi?id=210055
Signed-off-by: Necip Fazil Yildiran <fazilyildiran@xxxxxxxxx>
---
 drivers/staging/ralink-gdma/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/staging/ralink-gdma/Kconfig b/drivers/staging/ralink-gdma/Kconfig
index 54e8029e6b1a..0017376234e2 100644
--- a/drivers/staging/ralink-gdma/Kconfig
+++ b/drivers/staging/ralink-gdma/Kconfig
@@ -2,6 +2,7 @@
 config DMA_RALINK
 	tristate "RALINK DMA support"
 	depends on RALINK && !SOC_RT288X
+	depends on DMADEVICES
 	select DMA_ENGINE
 	select DMA_VIRTUAL_CHANNELS
 
-- 
2.25.1