[SYCL][ESIMD][E2E] Run aot_mixed.cpp only on Gen12 for now (#12630)
If we pass `%gpu_aot_target_opt` that compiles for all GPUs and we hit
an ocloc bug when compiling for xe-lpgplus-a0 in the new driver. This is
blocking driver uplift. I will make an internal ticket for the IGC team.
Signed-off-by: Sarnie, Nick <nick.sarnie@intel.com>