brcmfmac: Fix kernel oops in failed chip_attach

When chip attach fails, brcmf_sdiod_intr_unregister is being called
but that is too early as sdiodev->settings has not been set yet
nor has brcmf_sdiod_intr_register been called.
Change to use oob_irq_requested + newly created sd_irq_requested
to decide on what to unregister at intr_unregister time.

Steps to reproduce problem:
- modprobe brcmfmac using buggy FW
- rmmod brcmfmac
- modprobe brcmfmac again.

If done with a buggy firmware, brcm_chip_attach will fail on the
2nd modprobe triggering the call to intr_unregister and the
kernel oops when attempting to de-reference sdiodev->settings->bus.sdio
which has not yet been set.

Signed-off-by: Christian Daudt <csd@broadcom.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>