[PATCH] drm: rcar-du: fix linker undefined references

[Randy Dunlap <rdunlap@infradead.org>]

When DRM_RCAR_DU=y and DRM_RCAR_LVDS=m, there are several build errors
as reported by 'kernel test robot'. These can be corrected by changing
"imply" to "select".

In looking at this, the same problem (build errors) happens when
DRM_RCAR_DU=y and DRM_RCAR_CMM=m, so again change the "imply" to
"select" here as well.

These 2 changes fix the following 8 build/link errors:

aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
rcar_du_crtc.c:(.text+0x1be8): undefined reference to `rcar_lvds_clk_enable'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
rcar_du_crtc.c:(.text+0x2438): undefined reference to `rcar_lvds_clk_disable'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_drv.o: in function `rcar_du_init':
rcar_du_drv.c:(.init.text+0x14): undefined reference to `rcar_du_of_init'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_encoder.o: in function `rcar_du_encoder_init':
rcar_du_encoder.c:(.text+0x1d4): undefined reference to `rcar_lvds_dual_link'

aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_cmm_setup':
rcar_du_crtc.c:(.text+0x380): undefined reference to `rcar_cmm_setup'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_enable':
rcar_du_crtc.c:(.text+0x1c08): undefined reference to `rcar_cmm_enable'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_crtc.o: in function `rcar_du_crtc_atomic_disable':
rcar_du_crtc.c:(.text+0x231c): undefined reference to `rcar_cmm_disable'
aarch64-linux-ld: drivers/gpu/drm/rcar-du/rcar_du_kms.o: in function `rcar_du_modeset_init':
rcar_du_kms.c:(.text+0xd08): undefined reference to `rcar_cmm_init'

Fixes: e08e934d6c28 ("drm: rcar-du: Add support for CMM")
Fixes: 02f2b30032c1 ("drm: rcar-du: lvds: Add API to enable/disable clock output")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Masahiro Yamada <masahiroy@kernel.org>
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Cc: dri-devel@lists.freedesktop.org
Cc: linux-renesas-soc@vger.kernel.org
Cc: Jacopo Mondi <jacopo+renesas@jmondi.org>
---
 drivers/gpu/drm/rcar-du/Kconfig |    4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

--- linux-next-20210420.orig/drivers/gpu/drm/rcar-du/Kconfig
+++ linux-next-20210420/drivers/gpu/drm/rcar-du/Kconfig
@@ -4,8 +4,8 @@ config DRM_RCAR_DU
 	depends on DRM && OF
 	depends on ARM || ARM64
 	depends on ARCH_RENESAS || COMPILE_TEST
-	imply DRM_RCAR_CMM
-	imply DRM_RCAR_LVDS
+	select DRM_RCAR_CMM
+	select DRM_RCAR_LVDS
 	select DRM_KMS_HELPER
 	select DRM_KMS_CMA_HELPER
 	select DRM_GEM_CMA_HELPER