Juno: Use the generic ARM GIC driver

This patch replaces the usage of the GIC private driver in Juno with
the generic ARM GIC driver. The private driver is no longer necessary
and has been removed from the Juno port.

Fixes ARM-software/tf-issues#253

Change-Id: I6aaabc252e5e6fb5fcf44ab6d0febd9b38791056
diff --git a/plat/juno/tsp/tsp_plat_setup.c b/plat/juno/tsp/tsp_plat_setup.c
index 2d4ab81..0a9d4cb 100644
--- a/plat/juno/tsp/tsp_plat_setup.c
+++ b/plat/juno/tsp/tsp_plat_setup.c
@@ -80,6 +80,7 @@
  ******************************************************************************/
 void tsp_platform_setup(void)
 {
+	plat_gic_init();
 }
 
 /*******************************************************************************