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/backlight.h b/include/backlight.h
index ac59eb2..b44da50 100644
--- a/include/backlight.h
+++ b/include/backlight.h
@@ -7,6 +7,8 @@
 #ifndef _BACKLIGHT_H
 #define _BACKLIGHT_H
 
+struct udevice;
+
 enum {
 	BACKLIGHT_MAX		= 100,
 	BACKLIGHT_MIN		= 0,