intel: change urb max shader geometry for KBL GT1

intel: change urb max shader geometry for KBL GT1

Below Deqp CTS failure is seen on KBL GT1(tested on 0x5906) only ,
GT2 all test passes, changing the max shader geometry to 256
(previous 640) fixes all failure tests.Similar issues on
CML GT1 (Gen9) is fixed
https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8550

dEQP-GLES31.functional.geometry_shading.layered.
	 render_with_default_layer_cubemap
	 render_with_default_layer_3d
	 render_with_default_layer_2d_array

Signed-off-by: Abhishek Kumar <abhishek4.kumar@intel.com>
Reviewed-by: Lionel Landwerlin <lionel.g.landwerlin@intel.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/8731>