brcmfmac: always perform cores checks

Instead of checking the cores in the chip only if CONFIG_BRCMDBG
is selected perform the check always and extend it with more sanity
checking.

Reviewed-by: Hante Meuleman <meuleman@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>