drm/nouveau/nvfw/acr: set wpr_generic_header_dump storage-class-specifier to static

gcc with W=1 reports
drivers/gpu/drm/nouveau/nvkm/nvfw/acr.c:49:1: error: no previous
  prototype for ‘wpr_generic_header_dump’ [-Werror=missing-prototypes]
   49 | wpr_generic_header_dump(struct nvkm_subdev *subdev,
      | ^~~~~~~~~~~~~~~~~~~~~~~

wpr_generic_header_dump is only used in acr.c, so it should be static
Signed-off-by: Tom Rix <trix@redhat.com>
Reviewed-by: Karol Herbst <kherbst@redhat.com>
Signed-off-by: Karol Herbst <kherbst@redhat.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20230302124819.686469-1-trix@redhat.com

drivers/gpu/drm/nouveau/nvkm/nvfw/acr.c

@@ -45,7 +45,7 @@ wpr_header_v1_dump(struct nvkm_subdev *subdev, const struct wpr_header_v1 *hdr)
 	nvkm_debug(subdev, "\tstatus        : %d\n", hdr->status);
 }
 
-void
+static void
 wpr_generic_header_dump(struct nvkm_subdev *subdev, const struct wpr_generic_header *hdr)
 {
 	nvkm_debug(subdev, "wprGenericHeader\n");