mediatek/mt8173: Add PLL driver

Add PLL init code.

BRANCH=none
BUG=none
TEST=none

Change-Id: I2dcea8cdea1a3812bd8b84b7e8d961e7f8d4d953
Signed-off-by: Patrick Georgi <pgeorgi@chromium.org>
Original-Commit-Id: e6e2eecb2fad30db018685b61912103f5e2cd524
Original-Change-Id: Id67d8033f3b2a267a140d7d73daa5727bc032272
Original-Signed-off-by: James Liao <jamesjj.liao@mediatek.com>
Original-Reviewed-on: https://chromium-review.googlesource.com/292670
Original-Commit-Ready: Yidi Lin <yidi.lin@mediatek.com>
Original-Tested-by: Yidi Lin <yidi.lin@mediatek.com>
Original-Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-on: https://review.coreboot.org/12588
Tested-by: build bot (Jenkins)
Reviewed-by: Stefan Reinauer <stefan.reinauer@coreboot.org>
diff --git a/src/soc/mediatek/mt8173/Makefile.inc b/src/soc/mediatek/mt8173/Makefile.inc
index 74a7618..0d7957e 100644
--- a/src/soc/mediatek/mt8173/Makefile.inc
+++ b/src/soc/mediatek/mt8173/Makefile.inc
@@ -21,6 +21,7 @@
 
 bootblock-y += bootblock.c
 bootblock-y += cbfs.c
+bootblock-y += pll.c
 bootblock-y += timer.c
 
 ifeq ($(CONFIG_BOOTBLOCK_CONSOLE),y)