Remove concept of top/bottom image loading

This concept is no longer required since we now support loading of
images at fixed addresses only.

The image loader now automatically detects the position of the image
inside the current memory layout and updates the layout such that
memory fragmentation is minimised.

The 'attr' field of the meminfo data structure, which used to hold
the bottom/top loading information, has been removed. Also the 'next'
field has been removed as it wasn't used anywhere.

The 'init_bl2_mem_layout()' function has been moved out of common
code and put in BL1-specific code. It has also been renamed into
'bl1_init_bl2_mem_layout'.

Fixes ARM-software/tf-issues#109

Change-Id: I3f54642ce7b763d5ee3b047ad0ab59eabbcf916d
diff --git a/bl1/bl1_private.h b/bl1/bl1_private.h
index b54bf6b..0a8fc45 100644
--- a/bl1/bl1_private.h
+++ b/bl1/bl1_private.h
@@ -31,6 +31,15 @@
 #ifndef __BL1_PRIVATE_H__
 #define __BL1_PRIVATE_H__
 
+/*******************************************************************************
+ * Declarations of linker defined symbols which will tell us where BL1 lives
+ * in Trusted RAM
+ ******************************************************************************/
+extern uint64_t __BL1_RAM_START__;
+extern uint64_t __BL1_RAM_END__;
+#define BL1_RAM_BASE (uint64_t)(&__BL1_RAM_START__)
+#define BL1_RAM_LIMIT (uint64_t)(&__BL1_RAM_END__)
+
 /******************************************
  * Function prototypes
  *****************************************/