brcmfmac: don't realloc wiphy during PCIe reset

Providing a new wiphy on every PCIe reset was confusing and was causing
configuration problems for some users (supplicant and authenticators).
Sticking to the existing wiphy should make error recovery much simpler
and more reliable.

Signed-off-by: Rafał Miłecki <rafal@milecki.pl>
Acked-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>