drm/msm: Allow exported dma-bufs to be mapped

Currently msm does not implement gem_prime_mmap. Without this it is not
possible to draw onto a dma-buf from userspace (making its very hard to
implement the Android rendering model).

Fixing this is just a matter of adding a little boilerplate.

Signed-off-by: Daniel Thompson <daniel.thompson@linaro.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
diff --git a/drivers/gpu/drm/msm/msm_drv.c b/drivers/gpu/drm/msm/msm_drv.c
index b67ef59..5717d4e 100644
--- a/drivers/gpu/drm/msm/msm_drv.c
+++ b/drivers/gpu/drm/msm/msm_drv.c
@@ -832,6 +832,7 @@
 	.gem_prime_import_sg_table = msm_gem_prime_import_sg_table,
 	.gem_prime_vmap     = msm_gem_prime_vmap,
 	.gem_prime_vunmap   = msm_gem_prime_vunmap,
+	.gem_prime_mmap     = msm_gem_prime_mmap,
 #ifdef CONFIG_DEBUG_FS
 	.debugfs_init       = msm_debugfs_init,
 	.debugfs_cleanup    = msm_debugfs_cleanup,