common: Drop asm/global_data.h from common header

Move this out of the common header and include it only where needed.  In
a number of cases this requires adding "struct udevice;" to avoid adding
another large header or in other cases replacing / adding missing header
files that had been pulled in, very indirectly.   Finally, we have a few
cases where we did not need to include <asm/global_data.h> at all, so
remove that include.

Signed-off-by: Simon Glass <sjg@chromium.org>
Signed-off-by: Tom Rini <trini@konsulko.com>
diff --git a/include/ext_common.h b/include/ext_common.h
index bc33241..30a0c24 100644
--- a/include/ext_common.h
+++ b/include/ext_common.h
@@ -20,6 +20,8 @@
 #ifndef __EXT_COMMON__
 #define __EXT_COMMON__
 
+#include <compiler.h>
+
 struct cmd_tbl;
 
 #define SECTOR_SIZE		0x200