Blackfin: change global data register from P5 to P3

Since the Blackfin ABI favors higher scratch registers by default, use the
last scratch register (P3) for global data rather than the first (P5).
This allows the compiler's register allocator to use higher number scratch
P registers, which in turn better matches the Blackfin instruction set,
which reduces the size of U-Boot by more than 1024 bytes...

Signed-off-by: Robin Getz <robin.getz@analog.com>
Signed-off-by: Mike Frysinger <vapier@gentoo.org>
diff --git a/include/asm-blackfin/global_data.h b/include/asm-blackfin/global_data.h
index 5c9903b..3194b72 100644
--- a/include/asm-blackfin/global_data.h
+++ b/include/asm-blackfin/global_data.h
@@ -66,6 +66,6 @@
 #define	GD_FLG_LOGINIT	0x00020	/* Log Buf has been initialized	 */
 #define GD_FLG_DISABLE_CONSOLE	0x00040		/* Disable console (in & out)	 */
 
-#define DECLARE_GLOBAL_DATA_PTR     register gd_t * volatile gd asm ("P5")
+#define DECLARE_GLOBAL_DATA_PTR     register gd_t * volatile gd asm ("P3")
 
 #endif