drm/tegra: gem: Make __tegra_gem_mmap() available more widely

This function allows mapping a GEM object into a virtual memory address
space, which makes it useful outside of the GEM code.

While at it, rename the function so it doesn't clash with the function
that implements the DRM_TEGRA_GEM_MMAP IOCTL.

Signed-off-by: Thierry Reding <treding@nvidia.com>
diff --git a/drivers/gpu/drm/tegra/gem.h b/drivers/gpu/drm/tegra/gem.h
index 1fcf94d..6bd7dd7 100644
--- a/drivers/gpu/drm/tegra/gem.h
+++ b/drivers/gpu/drm/tegra/gem.h
@@ -70,6 +70,7 @@
 
 extern const struct vm_operations_struct tegra_bo_vm_ops;
 
+int __tegra_gem_mmap(struct drm_gem_object *gem, struct vm_area_struct *vma);
 int tegra_drm_mmap(struct file *file, struct vm_area_struct *vma);
 
 struct dma_buf *tegra_gem_prime_export(struct drm_device *drm,