zink: fix direct image mapping offset

the x and y offsets here were improperly calculated without taking into account:
* layer/level offset
* x/y coord bpp

Fixes: 8d46e35d16e ("zink: introduce opengl over vulkan")
Reviewed-by: Erik Faye-Lund <erik.faye-lund@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8058>
(cherry picked from commit 456b57802eaf95d36e7b950bdb5ffd86a1c0dc63)
2 files changed