fconf: Clean Arm IO

Merge the previously introduced arm_fconf_io_storage into arm_io_storage. This
removes the duplicate io_policies and functions definition.

This patch:
- replace arm_io_storage.c with the content of arm_fconf_io_storage.c
- rename the USE_FCONF_BASED_IO option into ARM_IO_IN_DTB.
- use the ARM_IO_IN_DTB option to compile out io_policies moved in dtb.
- propagate DEFINES when parsing dts.
- use ARM_IO_IN_DTB to include or not uuid nodes in fw_config dtb.
- set the ARM_IO_IN_DTB to 0 by default for fvp. This ensure that the behavior
  of fvp stays the same as it was before the introduction of fconf.

Change-Id: Ia774a96d1d3a2bccad29f7ce2e2b4c21b26c080e
Signed-off-by: Louis Mayencourt <louis.mayencourt@arm.com>
diff --git a/plat/arm/board/fvp/fdts/fvp_fw_config.dts b/plat/arm/board/fvp/fdts/fvp_fw_config.dts
index 9a4a057..2bb6c36 100644
--- a/plat/arm/board/fvp/fdts/fvp_fw_config.dts
+++ b/plat/arm/board/fvp/fdts/fvp_fw_config.dts
@@ -75,6 +75,7 @@
 	 * stored in machine order (little endian).
 	 * This will be fixed in future.
 	 */
+#if ARM_IO_IN_DTB
 	arm-io_policies {
 		fip-handles {
 			compatible = "arm,io-fip-handle";
@@ -99,6 +100,7 @@
 			nt_fw_content_cert_uuid = <0xf3c1c48e 0x11e4635d 0xee87a9a7 0xa73fb240>;
 		};
 	};
+#endif /* ARM_IO_IN_DTB */
 
 	secure-partitions {
 		compatible = "arm,sp";