Move DECLARE_GLOBAL_DATA_PTR to file scope

It can be optimised out by the compiler otherwise resulting
in obscure errors like a board not booting.

This has been documented in README since 2006 when these were
first fixed up for GCC 4.x.

Signed-off-by: John Rigby <john.rigby@linaro.org>

Fix some additional places.

Signed-off-by: Wolfgang Denk <wd@denx.de>
Acked-By: Albert ARIBAUD <albert.aribaud@free.fr>
diff --git a/arch/m68k/cpu/mcf547x_8x/speed.c b/arch/m68k/cpu/mcf547x_8x/speed.c
index 2cee488..31130b5 100644
--- a/arch/m68k/cpu/mcf547x_8x/speed.c
+++ b/arch/m68k/cpu/mcf547x_8x/speed.c
@@ -30,13 +30,13 @@
 
 #include <asm/immap.h>
 
+DECLARE_GLOBAL_DATA_PTR;
+
 /*
  * get_clocks() fills in gd->cpu_clock and gd->bus_clk
  */
 int get_clocks(void)
 {
-	DECLARE_GLOBAL_DATA_PTR;
-
 	gd->bus_clk = CONFIG_SYS_CLK;
 	gd->cpu_clk = (gd->bus_clk * 2);