NO_IRQ shouldn't be used by any driver. All Microblaze
drivers are fixed that's why NO_IRQ can be removed.

Also fix pci-common.c which has references to NO_IRQ removed.
Signed-off-by: NMichal Simek <monstr@monstr.eu>
Reviewed-by: NRyan Mallon <rmallon@gmail.com>
Acked-by: NGrant Likely <grant.likely@secretlab.ca>
CC: Benjamin Herrenschmidt <benh@kernel.crashing.org>