v3d: Support SAND128 base modifier

The BROADCOM_SAND128 modifier is usually used with an extra parameter
to pass in the stride via a side channel. Quoting from drm_fourcc.h:
> The pitch between the start of each column is set to optimally
> switch between SDRAM banks. This is passed as the number of lines
> of column width in the modifier (we can't use the stride value due
> to various core checks that look at it , so you should set the
> stride to width*cpp).

So apparently this is just a workaround for limitations in some kernel
APIs. DRM modifiers, however, are arguably a bad fit for extra
parameters that aren't known in advance. In the Wayland/KMS ecosystem
many components depend on being able to treat modifiers as opaque, e.g.
for negotiations etc. In practice the current approach requires various
software components to manually use the
`DRM_FORMAT_MOD_BROADCOM_SAND128_COL_HEIGHT()` macro - using the
`DRM_FORMAT_MOD_BROADCOM_SAND128` modifier directly with formats like
`NV12` results in a rejection in the KMS driver and corrupted output
in Mesa (because we'd bail out early in `v3d_sand8_blit()`).

Fortunately the stride check limitations mentioned above don't seem to
apply to Mesa though. Thus we can just add support for the base modifier
and stride (coming from V4L2), allowing various toolkits, Wayland
compositors and V4L2 decoder implementations to support e.g.
`NV12` + `DRM_FORMAT_MOD_BROADCOM_SAND128` (`NC12` in V4L2) in a generic
way.

Notes:
1. Wayland compositors trying to offload composition to KMS will still
fail when doing a test commit.
2. There is another limitation - in the V4L2 MPLANE API - that
requires userspace to know the correct offset of the second plane. That's
a known API limitation though and only affects V4L2 decoder implementations.

Cc: mesa-stable
Signed-off-by: Robert Mader <robert.mader@collabora.com>
Reviewed-by: Jose Maria Casanova Crespo <jmcasanova@igalia.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/32033>

src/gallium/drivers/v3d/v3d_resource.c

@@ -919,6 +919,10 @@ v3d_resource_from_handle(struct pipe_screen *pscreen,
         case DRM_FORMAT_MOD_INVALID:
                 rsc->tiled = false;
                 break;
+        case DRM_FORMAT_MOD_BROADCOM_SAND128:
+                rsc->tiled = false;
+                rsc->sand_col128_stride = whandle->stride;
+                break;
         default:
                 switch(fourcc_mod_broadcom_mod(whandle->modifier)) {
                 case DRM_FORMAT_MOD_BROADCOM_SAND128: