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/board/kontron/sl28/sl28.c b/board/kontron/sl28/sl28.c
index 34f17b4..d0372ac 100644
--- a/board/kontron/sl28/sl28.c
+++ b/board/kontron/sl28/sl28.c
@@ -5,6 +5,7 @@
 #include <errno.h>
 #include <fsl_ddr.h>
 #include <fdt_support.h>
+#include <asm/global_data.h>
 #include <linux/libfdt.h>
 #include <env_internal.h>
 #include <asm/arch-fsl-layerscape/soc.h>