AGESA: Move amd_initmmio() call

Function enables PCI MMCONF and XIP cache, it needs
to be called before giving platform any chance of
calling any PCI access functions.

Change-Id: Ic044d4df7b93667fa987c29c810d0bd826af87ad
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: https://review.coreboot.org/18623
Tested-by: build bot (Jenkins)
Reviewed-by: Philippe Mathieu-Daudé <philippe.mathieu.daude@gmail.com>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/include/cpu/amd/car.h

@@ -16,4 +16,6 @@ void cache_as_ram_new_stack(void);
 void disable_cache_as_ram(void);
 #endif
 
+void asmlinkage early_all_cores(void);
+
 #endif