brcmfmac: Use atomic functions for intstatus update.

brcmfmac: Use atomic functions for intstatus update.

The intstatus in sdio code can be updated from different
threads. To protect intstatus access, atomic functions are
used. One of them is set_bit, but this function is not
guaranteed atomic on all platforms. The loop was replaced
with local created OR function.

Reviewed-by: Arend Van Spriel <arend@broadcom.com>
Reviewed-by: Franky (Zhenhui) Lin <frankyl@broadcom.com>
Reviewed-by: Pieter-Paul Giesberts <pieterpg@broadcom.com>
Reviewed-by: Daniel (Deognyoun) Kim <dekim@broadcom.com>
Signed-off-by: Hante Meuleman <meuleman@broadcom.com>
Signed-off-by: Arend van Spriel <arend@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>