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/arch/x86/include/asm/arch-apollolake/systemagent.h b/arch/x86/include/asm/arch-apollolake/systemagent.h
index 788a63d..48e76c2 100644
--- a/arch/x86/include/asm/arch-apollolake/systemagent.h
+++ b/arch/x86/include/asm/arch-apollolake/systemagent.h
@@ -9,6 +9,9 @@
 
 /* Device 0:0.0 PCI configuration space */
 #include <linux/bitops.h>
+
+struct udevice;
+
 #define MCHBAR		0x48
 
 /* RAPL Package Power Limit register under MCHBAR */