brcmfmac: add out of band interrupt support

Some sdio host controllers do not support real in band interrupt.
Software polling mode as a replacement is not fast enough for
high throughput and new features. Also some in band interrupts
do not support host wake up on embedded platform even when they
are real physical interrupts. Therefore out of band (oob)
interrupt mechanism is implemented for these scenarios.

To provide oob irq number and flags used for irq registration in
brcmfmac, a platform device contains irq resource must be
registered in board specific code.

Here is an example of platform device structure:
struct resource brcmf_sdio_res[] = {
	{
		.start	= GPIO_BRCMF_SDIO_OOB_NUM,
		.end	= GPIO_BRCMF_SDIO_OOB_NUM,
		.flags  = IORESOURCE_IRQ | IORESOURCE_IRQ_HIGHLEVEL,
	}
};
struct platform_device brcmf_sdio_device = {
	.name		= "brcmf_sdio_pd",
	.id		= -1,
	.num_resources	= ARRAY_SIZE(brcmf_sdio_res),
	.resource	= brcmf_sdio_res,
};

Reviewed-by: pieter-paul giesberts <pieterpg@broadcom.com>
Reviewed-by: arend van spriel <arend@broadcom.com>
Signed-off-by: franky lin <frankyl@broadcom.com>
Signed-off-by: Franky Lin <frankyl@broadcom.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>