panfrost: fix get_image_width for 1D buffer images

Image size queries for buffer images were incorrectly using the
underlying buffer's width instead of the image view's size.

This affected `get_image_width` in OpenCL C for 1Dbuffer images, in
cases where the buffer is larger than the image to account for
padding, breaking the conformance test `test_kernel_image_methods
1Dbuffer`.

Fixes: 0efe7a6eb9 ("panfrost: implement image_size sysval")

Signed-off-by: Ahmed Hesham <ahmed.hesham@arm.com>
Reviewed-by: Boris Brezillon <boris.brezillon@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/38949>
(cherry picked from commit 95ed8d6638)

.pick_status.json

@@ -454,7 +454,7 @@
         "description": "panfrost: fix get_image_width for 1D buffer images",
         "nominated": true,
         "nomination_type": 2,
-        "resolution": 0,
+        "resolution": 1,
         "main_sha": null,
         "because_sha": "0efe7a6eb909b47fb24a7e15edcf4ee0d01cfd95",
         "notes": null

src/gallium/drivers/panfrost/pan_cmdstream.c

@@ -1126,7 +1126,7 @@ panfrost_upload_image_size_sysval(struct panfrost_batch *batch,
 
    if (image->resource->target == PIPE_BUFFER) {
       unsigned blocksize = util_format_get_blocksize(image->format);
-      uniform->i[0] = image->resource->width0 / blocksize;
+      uniform->i[0] = image->u.buf.size / blocksize;
       return;
    }