GBE: increase batch size to relax the max reloc restriction.

GBE: increase batch size to relax the max reloc restriction.

The drm will restrict the max reloc to (batch size)/8.
Current batch buffer size is 8K, then the max reloc is 1024.
As the max workgroup size is 1024, if it uses simd16 channel
then the thread_n will be 1024/16 = 64. And if it need to bind
32 buffers, then the reloc count will be 64*32 which is 2048
and exceed current limitation. Let's increase the batch size to
16K to relax this restrication to 2048 relocs.

Signed-off-by: Zhigang Gong <zhigang.gong@intel.com>
Reviewed-by: "Yang, Rong R" <rong.r.yang@intel.com>