ACPI: Allocate S3 resume backup in CBMEM earlier

These allocations are not really part of write_tables() and the move
opens possibilities to use CBMEM instead of SPI Flash to restore some
parts of system state after S3 resume.

Change-Id: I0c36bcee3f1da525af077fc1d18677ee85097e4d
Signed-off-by: Kyösti Mälkki <kyosti.malkki@gmail.com>
Reviewed-on: http://review.coreboot.org/7097
Tested-by: build bot (Jenkins)
Reviewed-by: Aaron Durbin <adurbin@google.com>

src/lib/hardwaremain.c

@@ -197,6 +197,8 @@ static boot_state_t bs_os_resume_check(void *arg)
 		boot_states[BS_OS_RESUME].arg = wake_vector;
 		return BS_OS_RESUME;
 	}
+
+	acpi_prepare_resume_backup();
 #endif
 	timestamp_add_now(TS_CBMEM_POST);