nv50: limit max code uploads to 0x8000

I have no idea why a bigger size doesn't work, the hardware doesn't
complain, but it turns out that uploading big shaders still causes issues
with the old limit. *shrug*

Fixes: 7f63d2ebdb ("nv50: fix code uploads bigger than 0x10000 bytes")
Signed-off-by: Karol Herbst <git@karolherbst.de>
Reviewed-by: M Henning <drawoc@darkrefraction.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/24758>

src/gallium/drivers/nouveau/nv50/nv50_transfer.c

@@ -280,7 +280,7 @@ nv50_sifc_linear_u8(struct nouveau_context *nv,
    struct nouveau_pushbuf *push = nv50->base.pushbuf;
    uint32_t *src = (uint32_t *)data;
    unsigned count = DIV_ROUND_UP(size, 4);
-   unsigned max_size = 0x10000;
+   unsigned max_size = 0x8000;
 
    nouveau_bufctx_refn(nv50->bufctx, 0, dst, domain | NOUVEAU_BO_WR);
    nouveau_pushbuf_bufctx(push, nv50->bufctx);