genirq: Add handle_fasteoi_{level,edge}_irq flow handlers

Follow-on patch for gpio-thunderx uses a irqdomain hierarchy which
requires slightly different flow handlers, add them to chip.c which
contains most of the other flow handlers.  Make these conditionally
compiled based on CONFIG_IRQ_FASTEOI_HIERARCHY_HANDLERS.

Signed-off-by: David Daney <david.daney@cavium.com>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Cc: Mark Rutland <mark.rutland@arm.com>
Cc: Alexandre Courbot <gnurou@gmail.com>
Cc: Marc Zyngier <marc.zyngier@arm.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: linux-gpio@vger.kernel.org
Link: http://lkml.kernel.org/r/1503017616-3252-3-git-send-email-david.daney@cavium.com