net: brcmfmac: Replace in_interrupt()

brcmf_sdio_isr() is using in_interrupt() to distinguish if it is called
from a interrupt service routine or from a worker thread.

Passing such information from the calling context is preferred and
requested by Linus, so add an argument `in_isr' to brcmf_sdio_isr() and let
the callers pass the information about the calling context.

Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Reviewed-by: Arend van Spriel <arend.vanspriel@broadcom.com>
Acked-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: David S. Miller <davem@davemloft.net>