powerpc/kexec: Fix boundary case for book-e kexec memory limits

The KEXEC_*_MEMORY_LIMITs are inclusive addresses.  We define them as
2Gs as that is what we allow mapping via TLBs.  However, this should be
2G - 1 to be inclusive, otherwise if we have >2G of memory in a system
we fail to boot properly via kexec.
Signed-off-by: Kumar Gala <galak@kernel.crashing.org>

arch/powerpc/include/asm/kexec.h

@@ -8,9 +8,9 @@
  * On FSL-BookE we setup a 1:1 mapping which covers the first 2GiB of memory
  * and therefore we can only deal with memory within this range
  */
-#define KEXEC_SOURCE_MEMORY_LIMIT	(2 * 1024 * 1024 * 1024UL)
-#define KEXEC_DESTINATION_MEMORY_LIMIT	(2 * 1024 * 1024 * 1024UL)
-#define KEXEC_CONTROL_MEMORY_LIMIT	(2 * 1024 * 1024 * 1024UL)
+#define KEXEC_SOURCE_MEMORY_LIMIT	(2 * 1024 * 1024 * 1024UL - 1)
+#define KEXEC_DESTINATION_MEMORY_LIMIT	(2 * 1024 * 1024 * 1024UL - 1)
+#define KEXEC_CONTROL_MEMORY_LIMIT	(2 * 1024 * 1024 * 1024UL - 1)
 
 #else