drm/i915: s/gen8_setup_page_directory_pointer/gen8_setup_pml4e/

The function name gen8_setup_page_directory_pointer is misleading, and
only serves to confuse the reader, it's not setting up a pdp, but
rather encoding a specific pml4e with a given pdp.

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

@@ -642,7 +642,7 @@ gen8_setup_pdpe(struct i915_hw_ppgtt *ppgtt,
 }
 
 static void
-gen8_setup_page_directory_pointer(struct i915_hw_ppgtt *ppgtt,
+gen8_setup_pml4e(struct i915_hw_ppgtt *ppgtt,
 		 struct i915_pml4 *pml4,
 		 struct i915_page_directory_pointer *pdp,
 		 int index)
@@ -1425,7 +1425,7 @@ static int gen8_alloc_va_range_4lvl(struct i915_address_space *vm,
 		if (ret)
 			goto err_out;
 
-		gen8_setup_page_directory_pointer(ppgtt, pml4, pdp, pml4e);
+		gen8_setup_pml4e(ppgtt, pml4, pdp, pml4e);
 	}
 
 	bitmap_or(pml4->used_pml4es, new_pdps, pml4->used_pml4es,