mediatek: Move mtcmos code to a common directory

Move mtcmos code which can be reused into a common directory under
soc/mediatek.

BUG=b:80501386
BRANCH=none
TEST=Boots correctly on Elm

Change-Id: I92b138890424b4f4a68cdb00bf2326eef9cd87b7
Signed-off-by: Tristan Shieh <tristan.shieh@mediatek.com>
Reviewed-on: https://review.coreboot.org/27029
Reviewed-by: Julius Werner <jwerner@chromium.org>
Reviewed-by: Paul Kocialkowski <contact@paulk.fr>
Reviewed-by: Hung-Te Lin <hungte@chromium.org>
Reviewed-by: Paul Menzel <paulepanter@users.sourceforge.net>
Tested-by: build bot (Jenkins) <no-reply@coreboot.org>

src/soc/mediatek/common/include/soc/mtcmos.h

@@ -1,7 +1,7 @@
 /*
  * This file is part of the coreboot project.
  *
- * Copyright 2015 MediaTek Inc.
+ * Copyright 2018 MediaTek Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/soc/mediatek/common/mtcmos.c

@@ -1,7 +1,7 @@
 /*
  * This file is part of the coreboot project.
  *
- * Copyright 2015 MediaTek Inc.
+ * Copyright 2018 MediaTek Inc.
  *
  * This program is free software; you can redistribute it and/or modify
  * it under the terms of the GNU General Public License as published by

src/soc/mediatek/mt8173/Makefile.inc

@@ -66,7 +66,7 @@ romstage-y += rtc.c
 ramstage-y += ../common/cbmem.c emi.c
 ramstage-y += spi.c
 ramstage-$(CONFIG_SPI_FLASH) += flash_controller.c
-ramstage-y += soc.c mtcmos.c
+ramstage-y += soc.c ../common/mtcmos.c
 ramstage-y += ../common/timer.c
 ramstage-y += timer.c
 ramstage-$(CONFIG_DRIVERS_UART) += ../common/uart.c