HiP04 GIC is the variate of ARM GICv2.

ARM GICv2 supports 8 cores. HiP04 GIC extends to support 16 cores. It
results that bit fields in GIC_DIST_TARGET & GIC_DIST_SOFTINT are
different from ARM GICv2. And the maximium IRQ is downgrade from 1020 to 510.

Since different register offset & bitfields definitation breaks
compartible with ARM GICv2, create a new hip04 irq driver.

And this driver is derived from irq-gic.c to support the Hisilicon HiP04
interrupt controller, which is similar to the GIC, but deviates at some
points. Support for power management, non-banked registers, cascaded
GICs (and multiple controllers in general) and bigLittle support has
been removed from the GIC driver.

Affinity related functions have been adjusted to match the Hisilicon
hardware implementation.
Signed-off-by: Haojian Zhuang <haojian.zhuang@linaro.org>
Link: https://lkml.kernel.org/r/1407408695-19626-9-git-send-email-haojian.zhuang@linaro.orgSigned-off-by: Jason Cooper <jason@lakedaemon.net>