dts: nxp_mcxn94x: fix flash write-block-size

- Fix mcxn94x flash write-block-size from 16 to 128.
- Fix flash_program() return error 0x65,
  that means "Address or length does not meet the required alignment."
- The mcxn94x Flash ROM API flash_program() start address and
  the length must be 128 bytes-aligned.

Signed-off-by: Andrej Butok <andrey.butok@nxp.com>