dt-bindings: clock: remove deprecated LSI AXM5516 clock bindings

commit  e4b7fcfcd118b14395b45fb997980fbe7ae7ffb3 from
https://github.com/axxia/linux-yocto.git

 v5.10/standard/preempt-rt/axxia-dev/base

The clock definitions for Intel Axxia AXM55xx was simplified in
the device tree.
Only the peripheral clock frequency is needed and it is fixed.
The boot loader will determine the frequency and update
the device tree before booting Linux.

Remove deprecated LSI AXM5516 clock bindings.

Signed-off-by: John Jacques <john.jacques@intel.com>
Signed-off-by: Charlie Paul <charlie.paul@windriver.com>
Signed-off-by: Daniel Dragomir <Daniel.Dragomir@windriver.com>
Signed-off-by: Quanyang Wang <quanyang.wang@windriver.com>