ARM: dts: am437x/am33xx/da850: Add new ECAP and EPWM bindings

Switch to a new ECAP and EPWM bindings that doesn't depend on hwmod to
provide the various required clocks.

For AM437 and AM335x, add the required clocks explicitly to DT. The
hwmod entries for ECAP and EPWM will be removed and this will prevent
anything from breaking.

Signed-off-by: Franklin S Cooper Jr <fcooper@ti.com>
Acked-by: Rob Herring <robh@kernel.org>
Signed-off-by: Tony Lindgren <tony@atomide.com>