intel/broadwell: Build monotonic timer driver for SMM

SPI flash drivers need it.

Change-Id: I63d79472d70d75f7907e7620755c228d5a4918e1
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Reviewed-on: http://review.coreboot.org/10033
Tested-by: build bot (Jenkins)
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Reviewed-by: Aaron Durbin <adurbin@chromium.org>

src/soc/intel/broadwell/Makefile.inc

@@ -33,6 +33,7 @@ ramstage-y += memmap.c
 romstage-y += memmap.c
 ramstage-y += minihd.c
 ramstage-y += monotonic_timer.c
+smm-y      += monotonic_timer.c
 ramstage-y += pch.c
 romstage-y += pch.c
 ramstage-y += pcie.c