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/drivers/xen/pvblock.c b/drivers/xen/pvblock.c
index 6455dfd..1c5d039 100644
--- a/drivers/xen/pvblock.c
+++ b/drivers/xen/pvblock.c
@@ -11,6 +11,7 @@
 #include <part.h>
 
 #include <asm/armv8/mmu.h>
+#include <asm/global_data.h>
 #include <asm/io.h>
 #include <asm/xen/system.h>