staging: fsl-mc: drop useless gic v3 related #include

Nothing from linux/irqchip/arm-gic-v3.h is used, so the #include can be
safely dropped.

Signed-off-by: Laurentiu Tudor <laurentiu.tudor@nxp.com>
Acked-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>