counter: mcux_lptmr: fix prescaler/glitch filter configuration

Fix incorrect LPTMR prescaler/glitch filter mapping that led to wrong
frequency calculation and wrong hardware configuration.

- Calculate effective counter frequency correctly:
  * Time Counter mode: divide by 2^(value + 1)
  * Pulse Counter mode: divide by 2^value
- Map prescale-glitch-filter directly to the HAL enum (no offset math)
- Add prescale-glitch-filter-bypass DT boolean (default false)
- Restrict prescale-glitch-filter to 0..15 and update bindings/DTS users
- Add build-time validation for Pulse mode (value 0 requires bypass)

Signed-off-by: Holt Sun <holt.sun@nxp.com>