lib: compile mdelay for romstage

Mimicking change I7037308d2, always compile mdelay for romstage.
The boards that #included delay.c in the romstage now rely on the linker
instead, which is a desirable cleanup.

Change-Id: I7e5169ec94e5417536e967194e8eab67381e7c98
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: https://review.coreboot.org/13115
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/mainboard/gigabyte/m57sli/romstage.c b/src/mainboard/gigabyte/m57sli/romstage.c
index 707ddc9..67bf503 100644
--- a/src/mainboard/gigabyte/m57sli/romstage.c
+++ b/src/mainboard/gigabyte/m57sli/romstage.c
@@ -28,7 +28,7 @@
 #include <cpu/amd/model_fxx_rev.h>
 #include "southbridge/nvidia/mcp55/early_smbus.c"
 #include <northbridge/amd/amdk8/raminit.h>
-#include "lib/delay.c"
+#include <delay.h>
 #include <cpu/x86/lapic.h>
 #include "northbridge/amd/amdk8/reset_test.c"
 #include <superio/ite/common/ite.h>