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

From: Rob Herring <rob.herring at calxeda.com>

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

Signed-off-by: Rob Herring <rob.herring at calxeda.com>
Cc: Thomas Gleixner <tglx at linutronix.de>
Cc: Hartley Sweeten <hsweeten at visionengravers.com>
Cc: Ryan Mallon <rmallon at gmail.com>
Cc: Russell King <linux at arm.linux.org.uk>
Cc: Alessandro Rubini <rubini at unipv.it>
Cc: Linus Walleij <linus.walleij at linaro.org>
Cc: STEricsson <STEricsson_nomadik_linux at list.st.com>
Cc: Ben Dooks <ben-linux at fluff.org>
Cc: Kukjin Kim <kgene.kim at samsung.com>
Cc: linux-samsung-soc at vger.kernel.org