arm64: dts: ti: k3-j721e-sk-*: Add DTB overlay to enable EHRPWMs

commit a430178d12c87a94f7bb20d138dcda6fe1ab4861 from
git://git.ti.com/ti-linux-kernel/ti-linux-kernel.git



Add DTB overlay to enable EHRPWM 2 and 3 and add pinmux
to bring them out on RPi expansion header

Signed-off-by: Rahul T R <r-ravikumar@ti.com>
Signed-off-by: Xulin Sun <xulin.sun@windriver.com>