drivers: counter: mcux_lptmr: Updated lptmr to support multi instance.

Updated the counter_mcux_lptmr driver to support multiple
instances of the lptmr peripheral. Also added a new
binding property to identify if the user is using
counter-mode or pulse mode. since we were previously using the
prescaler value to check this which could be wrong
if used as a division value for getting the freq.
Added a property that allows the user to decide
what the counter value in lptmr should be divided by.
Cleaned up INIT macro for lptmr.

Signed-off-by: Emilio Benavente <emilio.benavente@nxp.com>