ARM: PSCI: remove unnecessary include of arm-gic.h

Now that gic_secondary_init is no longer needed to be called by SMP init
functions, the header is not needed.
Signed-off-by: NRob Herring <rob.herring@calxeda.com>
Cc: Russell King <linux@arm.linux.org.uk>

arch/arm/kernel/psci_smp.c

@@ -14,7 +14,6 @@
  */
 
 #include <linux/init.h>
-#include <linux/irqchip/arm-gic.h>
 #include <linux/smp.h>
 #include <linux/of.h>