drm/i915: s/gen8_setup_page_directory/gen8_setup_pdpe/

The function name gen8_setup_page_directory is misleading, and only
serves to confuse the reader, it's not setting up a pd, but rather
encoding a specific pdpe with a given pd.

Cc: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>
Cc: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Matthew Auld <matthew.auld@intel.com>
Reviewed-by: Chris Wilson <chris@chris-wilson.co.uk>
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@linux.intel.com>

drivers/gpu/drm/i915/i915_gem_gtt.c

@@ -626,7 +626,7 @@ static void gen8_initialize_pml4(struct i915_address_space *vm,
 }
 
 static void
-gen8_setup_page_directory(struct i915_hw_ppgtt *ppgtt,
+gen8_setup_pdpe(struct i915_hw_ppgtt *ppgtt,
 		struct i915_page_directory_pointer *pdp,
 		struct i915_page_directory *pd,
 		int index)
@@ -1366,7 +1366,7 @@ static int gen8_alloc_va_range_3lvl(struct i915_address_space *vm,
 
 		kunmap_px(ppgtt, page_directory);
 		__set_bit(pdpe, pdp->used_pdpes);
-		gen8_setup_page_directory(ppgtt, pdp, pd, pdpe);
+		gen8_setup_pdpe(ppgtt, pdp, pd, pdpe);
 	}
 
 	free_gen8_temp_bitmaps(new_page_dirs, new_page_tables);