drm/i915: align the plane_vma to min_page_size of stolen mem

Align the plane vma size to the stolem memory regions' min_page_size.

Signed-off-by: Ramalingam C <[e-mail]>
cc: Matthew Auld <[e-mail]>
cc: Chris P Wilson <[e-mail]>
Reviewed-by: Matthew Auld <[e-mail]>
Link: https://patchwork.freedesktop.org/patch/msgid/[e-mail]

drivers/gpu/drm/i915/display/intel_plane_initial.c

···
 initial_plane_vma(struct drm_i915_private *i915,
 		  struct intel_initial_plane_config *plane_config)
 {
+	struct intel_memory_region *mem = i915->mm.stolen_region;
 	struct drm_i915_gem_object *obj;
 	struct i915_vma *vma;
 	u32 base, size;
 
-	if (plane_config->size == 0)
+	if (!mem || plane_config->size == 0)
 		return NULL;
 
 	base = round_down(plane_config->base,
 			  I915_GTT_MIN_ALIGNMENT);
 	size = round_up(plane_config->base + plane_config->size,
-			I915_GTT_MIN_ALIGNMENT);
+			mem->min_page_size);
 	size -= base;
 
 	/*