Replace ENV_RAMSTAGE with ENV_PAYLOAD_LOADER

This patch relying on new rule, ENV_PAYLOAD_LOADER which is set
to ENV_RAMSTAGE.

This approach will help to add future optimization (rampayload) in
coreboot flow if required.

Change-Id: Ib54ece7b9e5f281f8a092dc6f38c07406edfa5fa
Signed-off-by: Subrata Banik <subrata.banik@intel.com>
Reviewed-on: https://review.coreboot.org/c/coreboot/+/32725
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: ron minnich <rminnich@gmail.com>

src/include/rules.h

@@ -277,7 +277,7 @@
  * be built with simple device model.
  */
 
-#if (defined(__PRE_RAM__) || ENV_SMM || ENV_POSTCAR)
+#if (defined(__PRE_RAM__) || ENV_SMM || !ENV_PAYLOAD_LOADER)
 #define __SIMPLE_DEVICE__
 #endif