misc: xlnx_dpu: Dual license update for DPU header driver: GPL + Apache

commit c56b694922ca540401a9fcae4a14d9262bdd4c56 from
https://github.com/Xilinx/linux-xlnx.git

 xlnx_rebase_v5.15

Update License for DPU kernel header driver to dual GPL2/Apache2

Signed-off-by: Ye Yang <ye.yang@amd.com>
State: pending
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>