dt-bindings: watchdog: xps-timebase: Align filename

commit 0ece2206de13ec176a884110b84b75c041a96de8 from
https://github.com/Xilinx/linux-xlnx.git

 xlnx_rebase_v5.15

Aligned id http link with file name. Both of them should match.

Signed-off-by: Michal Simek <michal.simek@amd.com>
State: pending
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>