arm64: dts: ti: k3-am65/j721e-mcu: update cpts node

Update CPTS node following DT binding update:
 - add reg and compatible properties
 - fix node name

Signed-off-by: Grygorii Strashko <grygorii.strashko@ti.com>
Signed-off-by: David S. Miller <davem@davemloft.net>