arm64: dts: ti: k3-j721s2-main: Add dts nodes for EHRPWMs

Add dts nodes for 6 EHRPWM instances on SoC. Disable EHRPWM nodes in the
dtsi files and only enable the ones that are actually pinned out on a
given board in the board dts file.

Signed-off-by: Sinthu Raja <sinthu.raja@ti.com>
Link: https://lore.kernel.org/r/20230721082150.12599-1-sinthu.raja@ti.com


Signed-off-by: Nishanth Menon <nm@ti.com>