Juno: Use TZC-400 driver calls

This patch replaces direct accesses to the TZC-400 registers by the
appropiate calls to the generic driver available in the Trusted
Firmware in order to initialize the TrustZone Controller.

Functions related to the initialization of the secure memory,
like the TZC-400 configuration, have been moved to a new file
'plat_security.c'. This reorganization makes easier to set up
the secure memory from any BL stage.

TZC-400 initialization has been moved from BL1 to BL2 because BL1
does not access the non-secure memory. It is BL2's responsibility
to enable and configure the TZC-400 before loading the next BL
images.

In Juno, BL3-0 initializes some of the platform peripherals, like
the DDR controller. Thus, BL3-0 must be loaded before configuring
the TrustZone Controller. As a consequence, the IO layer
initialization has been moved to early platform initialization.

Fixes ARM-software/tf-issues#234

Change-Id: I83dde778f937ac8d2996f7377e871a2e77d9490e
diff --git a/bl2/bl2_main.c b/bl2/bl2_main.c
index 51c55e0..a73946e 100644
--- a/bl2/bl2_main.c
+++ b/bl2/bl2_main.c
@@ -199,9 +199,6 @@
 	/* Perform remaining generic architectural setup in S-EL1 */
 	bl2_arch_setup();
 
-	/* Perform platform setup in BL2 */
-	bl2_platform_setup();
-
 	/*
 	 * Load the subsequent bootloader images
 	 */
@@ -211,6 +208,9 @@
 		panic();
 	}
 
+	/* Perform platform setup in BL2 after loading BL3-0 */
+	bl2_platform_setup();
+
 	/*
 	 * Get a pointer to the memory the platform has set aside to pass
 	 * information to BL3-1.