build(msm8916): place bl32 directly after bl31

At the moment there are two entirely separate memory regions for BL31
and BL32. However, since BL31 is very small (<= 128 KiB) there is
actually still plenty of space after BL31.

Drop the extra memory region for BL32 and place it directly after BL31
(i.e. BL31_LIMIT). If needed it is still possible to change it on the
make command line.

While at it, move the definitions to the bottom of the make file so
they come immediately before the related add_define calls.

Change-Id: I5184dcc2d89a92f1384508f973d56fd963e7befb
Signed-off-by: Stephan Gerhold <stephan@gerhold.net>
diff --git a/plat/qti/msm8916/include/platform_def.h b/plat/qti/msm8916/include/platform_def.h
index 6d5ff2b..02bfd37 100644
--- a/plat/qti/msm8916/include/platform_def.h
+++ b/plat/qti/msm8916/include/platform_def.h
@@ -18,6 +18,7 @@
  */
 #define BL31_LIMIT			(BL31_BASE + SZ_128K)
 #define BL31_PROGBITS_LIMIT		(BL31_BASE + SZ_64K)
+#define BL32_LIMIT			(BL32_BASE + SZ_128K)
 
 #define CACHE_WRITEBACK_GRANULE		U(64)
 #define PLATFORM_STACK_SIZE		SZ_4K