zephyr: nrf_wifi: Update RPU patch to rev#b6fcc574a37#1837

rlubos merged 1 commit intonrfconnect:mainnrfconnect/sdk-nrfxlib:mainfrom

karun2796:twt_timeout_nrfxlibkarun2796/sdk-nrfxlib:twt_timeout_nrfxlibCopy head branch name to clipboard