lib: Add delay.c to smm

BUG=b:74083107

Change-Id: I98ab5c84268e8754fbaf6a30cd26fe1084e45a20
Signed-off-by: Furquan Shaikh <furquan@google.com>
Reviewed-on: https://review.coreboot.org/24963
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>

src/lib/Makefile.inc

@@ -175,6 +175,7 @@ romstage-y += boot_device.c
 ramstage-y += boot_device.c
 
 smm-y += boot_device.c
+smm-y += delay.c
 smm-y += fmap.c
 smm-y += cbfs.c memcmp.c
 smm-$(CONFIG_GENERIC_UDELAY) += timer.c