soc: nxp: Add missing resolve of system timer cfg

These socs were missing a config line to disable SYSTICK if the LPTMR is
configured for the system timer, similar to how other SOCs do this for
alternative system timers than systick.

This fixes build errors in the case where that lptmr kconfig is enabled.

Also, the LPTMR kconfig should be default no because it is a secondary
option for the system timer, being lower resolution than systick. This
also resolves build errors.

Signed-off-by: Declan Snyder <declan.snyder@nxp.com>