arm64: dts: ti: k3-am65-main: Drop RNG clock

The x1-clk used by trng submodule comes directly from the system clock
after a fixed divider. It is always running and has a fixed frequency
that cannot be changed, making it uncontrollable. Hence this property
should be dropped from the rng node.

Signed-off-by: Jayesh Choudhary <j-choudhary@ti.com>
Reviewed-by: Manorit Chawdhry <m-chawdhry@ti.com>
Signed-off-by: Nishanth Menon <nm@ti.com>
Link: https://lore.kernel.org/r/20221107110607.59216-2-j-choudhary@ti.com