irqchip: Move ARM gic.h to include/linux/irqchip/arm-gic.h

Now that we have GIC moved to drivers/irqchip and all GIC DT init for
platforms using irqchip_init, move gic.h and update the remaining
includes.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Anton Vorontsov <avorontsov@mvista.com>
Cc: Kukjin Kim <kgene.kim@samsung.com>
Cc: Sascha Hauer <kernel@pengutronix.de>
Cc: David Brown <davidb@codeaurora.org>
Cc: Daniel Walker <dwalker@fifo99.com>
Cc: Bryan Huntsman <bryanh@codeaurora.org>
Cc: Tony Lindgren <tony@atomide.com>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: Magnus Damm <magnus.damm@gmail.com>
Cc: Viresh Kumar <viresh.linux@gmail.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Cc: Stephen Warren <swarren@wwwdotorg.org>
Cc: Srinidhi Kasagar <srinidhi.kasagar@stericsson.com>
Cc: Linus Walleij <linus.walleij@linaro.org>
Cc: Samuel Ortiz <sameo@linux.intel.com>

arch/arm/mach-omap2/omap4-common.c

@@ -21,8 +21,8 @@
 #include <linux/of_irq.h>
 #include <linux/of_platform.h>
 #include <linux/export.h>
+#include <linux/irqchip/arm-gic.h>
 
-#include <asm/hardware/gic.h>
 #include <asm/hardware/cache-l2x0.h>
 #include <asm/mach/map.h>
 #include <asm/memblock.h>