drm/i915: Increase I915_PARAM_MMAP_GTT_VERSION version to indicate support for partial mmaps

Commit 255fc17 ("drm/i915/gem: Calculate object page offset for partial memory mapping")
was the last patch of several patches fixing multiple partial mmaps.
But without a bump in I915_PARAM_MMAP_GTT_VERSION there is no clean
way for UMD to know if it can do multiple partial mmaps.

Fixes: 255fc17 ("drm/i915/gem: Calculate object page offset for partial memory mapping")
Cc: Andi Shyti <[email protected]>
Cc: Nirmoy Das <[email protected]>
Cc: Lionel Landwerlin <[email protected]>
Signed-off-by: José Roberto de Souza <[email protected]>
Reviewed-by: Nirmoy Das <[email protected]>
Link: https://patchwork.freedesktop.org/patch/msgid/[email protected]
(cherry picked from commit bfef148)
Signed-off-by: Rodrigo Vivi <[email protected]>

Author: zehortigoza

drivers/gpu/drm/i915/gem/i915_gem_mman.c

@@ -164,6 +164,9 @@ static unsigned int tile_row_pages(const struct drm_i915_gem_object *obj)
  * 4 - Support multiple fault handlers per object depending on object's
  *     backing storage (a.k.a. MMAP_OFFSET).
  *
+ * 5 - Support multiple partial mmaps(mmap part of BO + unmap a offset, multiple
+ *     times with different size and offset).
+ *
  * Restrictions:
  *
  *  * snoopable objects cannot be accessed via the GTT. It can cause machine
@@ -191,7 +194,7 @@ static unsigned int tile_row_pages(const struct drm_i915_gem_object *obj)
  */
 int i915_gem_mmap_gtt_version(void)
 {
-	return 4;
+	return 5;
 }
 
 static inline struct i915_gtt_view