[PATCH -next] drm/rcar-du: Fix undefined reference error

[Ren Zhijie]

If DRM_RCAR_MIPI_DSI=m and DRM_RCAR_DU=y,
gcc complained about undefined reference :

drivers/gpu/drm/rcar-du/rcar_du_crtc.o: In function `rcar_du_crtc_atomic_enable':
rcar_du_crtc.c:(.text+0x1958): undefined reference to `rcar_mipi_dsi_pclk_enable'
drivers/gpu/drm/rcar-du/rcar_du_crtc.o: In function `rcar_du_crtc_atomic_disable':
rcar_du_crtc.c:(.text+0x3cf4): undefined reference to `rcar_mipi_dsi_pclk_disable'

To fix this error, add select DRM_RCAR_MIPI_DSI dependency to config DRM_RCAR_DU.

Fixes: 957fe62d7d15 ("drm: rcar-du: Fix DSI enable & disable sequence")
Signed-off-by: Ren Zhijie <renzhijie2 at huawei.com>
---
 drivers/gpu/drm/rcar-du/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/gpu/drm/rcar-du/Kconfig b/drivers/gpu/drm/rcar-du/Kconfig
index c959e8c6be7d..23f6aa70f4cf 100644
--- a/drivers/gpu/drm/rcar-du/Kconfig
+++ b/drivers/gpu/drm/rcar-du/Kconfig
@@ -7,6 +7,7 @@ config DRM_RCAR_DU
 	select DRM_KMS_HELPER
 	select DRM_GEM_DMA_HELPER
 	select VIDEOMODE_HELPERS
+	select DRM_RCAR_MIPI_DSI
 	help
 	  Choose this option if you have an R-Car chipset.
 	  If M is selected the module will be called rcar-du-drm.
-- 
2.17.1