The vulkan spec says that we should ignore memoryOffset when
VkBindImageMemorySwapchainInfoKHR is present. wsi common assumes that we
bind the wsi image at offset 0, so set the offset to 0. This change
aligns with common wsi, and also obeys dedicated alloc requirement.
Fixes: f887116c49 ("turnip: adopt wsi_common_get_memory")
Reviewed-by: Connor Abbott <cwabbott0@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/37099>