CFT: re(4) MSI support

Hi,

I've added MSI capability to re(4) and it would fix occasional
watchdog timeout erros seen on re(4) when its interrupt is shared
with other devices. The fix only affects PCIe based hardwares.
In these days, more and more hardwares use PCIe based hardwares
and these hardwares surly share interrupts with other devices.
If you ever encountered watchdog timeouts on re(4) with PCIe
hardwares please try attached patch and report back the result.

Thanks.
-- 
Regards,
Pyun YongHyeon