Add directive __SIMPLE_DEVICE__

The tests for __PRE_RAM__ or __SMM__ were repeatedly used
for detection if dev->ops in the devicetree are not available
and simple device model functions need be used.

If a source file build for ramstage had __PRE_RAM__ inserted
at the beginning, the struct device would no longer match the
allocation the object had taken. This problem is fixed by
replacing such cases with explicit __SIMPLE_DEVICE__.

Change-Id: Ib74c9b2d8753e6e37e1a23fcfaa2f3657790d4c0
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/3555
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/southbridge/amd/cimx/sb700/reset.c

@@ -17,9 +17,9 @@
  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
  */
 
-#ifndef __PRE_RAM__
-#define __PRE_RAM__ // Use simple device model for this file even in ramstage
-#endif
+// Use simple device model for this file even in ramstage
+#define __SIMPLE_DEVICE__
+
 #include <arch/io.h>
 #include <reset.h>