ARM: remove mach .handle_irq for VIC users

Now that the VIC initialization sets up the handle_arch_irq pointer, we
can remove it for all machines and make it static. Move vic_handle_irq
to avoid a forward declaration.

Signed-off-by: Rob Herring <rob.herring@calxeda.com>
Cc: Ryan Mallon <rmallon@gmail.com>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Hubert Feurstein <hubert.feurstein@contec.at>
Cc: Alessandro Rubini <rubini@unipv.it>
Cc: STEricsson <STEricsson_nomadik_linux@list.st.com>
Cc: Ben Dooks <ben-linux@fluff.org>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: Shiraz Hashim <shiraz.hashim@st.com>
Cc: Rajeev Kumar <rajeev-dlh.kumar@st.com>
Acked-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Acked-by: Jamie Iles <jamie@jamieiles.com>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Acked-by: Mark Brown <broonie@opensource.wolfsonmicro.com>
Acked-by: Viresh Kumar <viresh.kumar@linaro.org>
Acked-by: Kukjin Kim <kgene.kim@samsung.com>
Acked-by: Olof Johansson <olof@lixom.net>
Acked-by: Arnd Bergmann <arnd@arndb.de>