[PATCH] drm/hisilicon/hibmc: add back depends on MMU

[Randy Dunlap]

ARM64 always has CONFIG_MMU=y but adding a dependency on
COMPILE_TEST allows an arch with MMU optional (riscv in this case)
to build the hibmc driver, leading to a kconfig warning and
build errors, so restore the MMU dependency.

WARNING: unmet direct dependencies detected for DRM_TTM
  Depends on [n]: HAS_IOMEM [=y] && DRM [=y] && MMU [=n]
  Selected by [y]:
  - DRM_TTM_HELPER [=y] && HAS_IOMEM [=y] && DRM [=y]
  - DRM_HISI_HIBMC [=y] && HAS_IOMEM [=y] && DRM [=y] && PCI [=y] && (ARM64 || COMPILE_TEST [=y])

riscv64-linux-ld: drivers/gpu/drm/ttm/ttm_bo_vm.o: in function `.L97':
ttm_bo_vm.c:(.text+0x814): undefined reference to `vmf_insert_pfn_prot'
riscv64-linux-ld: drivers/gpu/drm/ttm/ttm_bo_vm.o: in function `.L0 ':
ttm_bo_vm.c:(.text+0x9d0): undefined reference to `vmf_insert_pfn_prot'

Fixes: a0f25a6bb319 ("drm/hisilicon/hibmc: Allow to be built if COMPILE_TEST is enabled")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Reported-by: kernel test robot <lkp@xxxxxxxxx>
Cc: Javier Martinez Canillas <javierm@xxxxxxxxxx>
Cc: Thomas Zimmermann <tzimmermann@xxxxxxx>
Cc: Xinliang Liu <xinliang.liu@xxxxxxxxxx>
Cc: Tian Tao  <tiantao6@xxxxxxxxxxxxx>
Cc: John Stultz <john.stultz@xxxxxxxxxx>
Cc: Xinwei Kong <kong.kongxinwei@xxxxxxxxxxxxx>
Cc: Chen Feng <puck.chen@xxxxxxxxxxxxx>
Cc: David Airlie <airlied@xxxxxxxx>
Cc: Daniel Vetter <daniel@xxxxxxxx>
Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx
---
 drivers/gpu/drm/hisilicon/hibmc/Kconfig |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/drivers/gpu/drm/hisilicon/hibmc/Kconfig
+++ b/drivers/gpu/drm/hisilicon/hibmc/Kconfig
@@ -1,7 +1,7 @@
 # SPDX-License-Identifier: GPL-2.0-only
 config DRM_HISI_HIBMC
 	tristate "DRM Support for Hisilicon Hibmc"
-	depends on DRM && PCI && (ARM64 || COMPILE_TEST)
+	depends on DRM && PCI && MMU && (ARM64 || COMPILE_TEST)
 	select DRM_KMS_HELPER
 	select DRM_VRAM_HELPER
 	select DRM_TTM