drivers: wifi: nxp: update Kconfig to support FW dump

Remove the redundant dependency of NXP_WIFI_EXTRA_DEBUG in Kconfig.
Add NXP_FW_DUMP_FLASH_START_ADDR for the start address in flash to
store FW dump.
Add NXP_FW_DUMP_FLASH_ERASE_LENGTH for the erased length in flash
to store FW dump.

Signed-off-by: Maochen Wang <maochen.wang@nxp.com>