anv/hasvk: Clamping Scissor Rect values in a valid range

anv/hasvk: Clamping Scissor Rect values in a valid range

On cmd_buffer_emit_scissor(), if VkViewport height or width are set to
a value lower than 1.0, y_max or x_max can be attributed negative values,
causing an overflow. That leads to ScissorRectangleYMax or
ScissorRectangleXMax to be set to values on an unsupported range.

Clamping x_max and y_max in the valid range solves the problem.

Closes: https://gitlab.freedesktop.org/mesa/mesa/-/issues/7471
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Cc: mesa-stable
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20200>