arm64: dts: ti: k3-am65-main: Add ICSSG IEP nodes

The ICSSG IP on AM65x SoCs have two Industrial Ethernet Peripherals (IEPs)
to manage/generate Industrial Ethernet functions such as time stamping.
Each IEP sub-module is sourced from an internal clock mux that can be
sourced from either of the IP instance's ICSSG_IEP_GCLK or ICSSG_ICLK.
Add the IEP nodes for all the ICSSG instances.

Signed-off-by: MD Danish Anwar <danishanwar@ti.com>
Link: https://lore.kernel.org/r/20231020051937.3709871-2-danishanwar@ti.com


Signed-off-by: Vignesh Raghavendra <vigneshr@ti.com>